NCBI Conserved Domain Search

Meprin, A5 protein, and protein tyrosine phosphatase Mu (MAM) domain. MAM is an extracellular domain which mediates protein-protein interactions and is found in a diverse set of proteins, many of which are known to function in cell adhesion. Members include: type IIB receptor protein tyrosine phosphatases (such as RPTPmu), meprins (plasma membrane metalloproteases), neuropilins (receptors of secreted semaphorins), and zonadhesins (sperm-specific membrane proteins which bind to the extracellular matrix of the egg). In meprin A and neuropilin-1 and -2, MAM is involved in homo-oligomerization. In RPTPmu, it has been associated with both homophilic adhesive (trans) interactions and lateral (cis) receptor oligomerization. In a GPI-anchored protein that is expressed in cells in the embryonic chicken spinal chord, MDGA1, the MAM domain has been linked to heterophilic interactions with axon-rich region.

Pssm-ID: 99706 Cd Length: 157 Bit Score: 215.70 E-value: 4.45e-65

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 753 CHFEDEkICGYTQDLTDNFDWTRQNALTQNPKRspntgPPTDISGTPEGYYMFIETSRPRElGDRARLVSPLYNASAKFY 832
Cdd:cd06263   1 CDFEDG-LCGWTQDSTDDFDWTRVSGSTPSPGT-----PPDHTHGTGSGHYLYVESSSGRE-GQKARLLSPLLPPPRSSH 73

                        90       100       110       120       130       140       150       160
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 833 CVSFFYHMYGKHIGSLNLLVRSrNKGALDTHAWSLSGNKGNVWQQAHVPIS-PSGPFQIIFEGVRGPGYLGDIAIDDVTL 911
Cdd:cd06263  74 CLSFWYHMYGSGVGTLNVYVRE-EGGGLGTLLWSASGGQGNQWQEAEVTLSaSSKPFQVVFEGVRGSGSRGDIALDDISL 152


                ....*
gi 24111244 912 KKGEC 916
Cdd:cd06263 153 SPGPC 157

MAM domain, meprin/A5/mu; An extracellular domain found in many receptors. The MAM domain along with the associated Ig domain in type IIB receptor protein tyrosine phosphatases forms a structural unit (termed MIg) with a seamless interdomain interface. It plays a major role in homodimerization of the phosphatase ectoprotein and in cell adhesion. MAM is a beta-sandwich consisting of two five-stranded antiparallel beta-sheets rotated away from each other by approx 25 degrees, and plays a similar role in meprin metalloproteinases.

Pssm-ID: 459878 [Multi-domain] Cd Length: 159 Bit Score: 214.92 E-value: 9.15e-65

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244   753 CHFEDEKICGYTQDLTDNFDWTRQNAltqnpkRSPNTGPPTDIS-GTPEGYYMFIETSRPRElGDRARLVSPLYNASAKF 831
Cdd:pfam00629   1 CDFEDGNLCGWTQDSSDDFDWERVSG------PSVKTGPSSDHTqGTGSGHFMYVDTSSGAP-GQTARLLSPLLPPSRSP 73

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244   832 YCVSFFYHMYGKHIGSLNLLVRSrNKGALDTHAWSLSGNKGNVWQQAHVPISP-SGPFQIIFEGVRGPGYLGDIAIDDVT 910
Cdd:pfam00629  74 QCLRFWYHMSGSGVGTLRVYVRE-NGGTLDTLLWSISGDQGPSWKEARVTLSSsTQPFQVVFEGIRGGGSRGGIALDDIS 152


                  ....*..
gi 24111244   911 LKKGECP 917
Cdd:pfam00629 153 LSSGPCP 159

Domain in meprin, A5, receptor protein tyrosine phosphatase mu (and others); Likely to have an adhesive function. Mutations in the meprin MAM domain affect noncovalent associations within meprin oligomers. In receptor tyrosine phosphatase mu-like molecules the MAM domain is important for homophilic cell-cell interactions.

Pssm-ID: 214533 [Multi-domain] Cd Length: 161 Bit Score: 171.76 E-value: 2.58e-49

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244    749 SDNTCHFEDEKICGYTQDLTDNFDWTRQNALTqnpkrsPNTGPPTDISgTPEGYYMFIETSRPRElGDRARLVSPLYNAS 828
Cdd:smart00137   2 SPGNCDFEEGSTCGWHQDSNDDGHWERVSSAT------GIPGPNRDHT-TGNGHFMFFETSSGAE-GQTARLLSPPLYEN 73

                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244    829 AKFYCVSFFYHMYGKHIGSLNLLVRSRNkGALDTHAWSLSGNKGNVWQQAHVPISPS-GPFQIIFEGVRGPGYLGDIAID 907
Cdd:smart00137  74 RSTHCLTFWYYMYGSGSGTLNVYVRENN-GSQDTLLWSRSGTQGGQWLQAEVALSSWpQPFQVVFEGTRGKGHSGYIALD 152


                   ....*....
gi 24111244    908 DVTLKKGEC 916
Cdd:smart00137 153 DILLSNGPC 161

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM), and similar domains; The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM and human neurofascin.

Pssm-ID: 409394 [Multi-domain] Cd Length: 83 Bit Score: 62.04 E-value: 6.61e-12

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 24111244  44 SERVYTIREGDTLMLQCLVTGHPRPQVRWTKTAGS-ASDKFQETSvFNETLRIERIARTQGGRYYCKAENGVG 115
Cdd:cd05731   1 SESSTMVLRGGVLLLECIAEGLPTPDIRWIKLGGElPKGRTKFEN-FNKTLKIENVSEADSGEYQCTASNTMG 72

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 61.81 E-value: 7.07e-12

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 24111244    43 ISERVYTIREGDTLMLQCLVTGHPRPQVRWTK---TAGSASDKFQETSVFNETLRIERIARTQGGRYYCKAEN 112
Cdd:pfam13927   6 VSPSSVTVREGETVTLTCEATGSPPPTITWYKngePISSGSTRSRSLSGSNSTLTISNVTRSDAGTYTCVASN 78

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 61.81 E-value: 7.14e-12

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 24111244   439 PPTISVPKGRavVTVREGSPAELQCEVRGKPRPPVLWSRVDKEAALLPSGLPLEETPDGKLRLERVSRDMSGTYRCQ 515
Cdd:pfam13927   1 KPVITVSPSS--VTVREGETVTLTCEATGSPPPTITWYKNGEPISSGSTRSRSLSGSNSTLTISNVTRSDAGTYTCV 75

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 61.75 E-value: 8.42e-12

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244    248 ETLVVNPGENVTVQCLLTGgDPLPQLQWSHGPGPLPLG-------ALAQGGTLSIPSVQARDSGYYNCTATNNVGNpAKK 320
Cdd:smart00410   2 PSVTVKEGESVTLSCEASG-SPPPEVTWYKQGGKLLAEsgrfsvsRSGSTSTLTISNVTPEDSGTYTCAATNSSGS-ASS 79


                   ....*.
gi 24111244    321 TVNLLV 326
Cdd:smart00410  80 GTTLTV 85

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 60.66 E-value: 2.17e-11

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244   239 PPALKLSVNETlVVNPGENVTVQCLLTGGdPLPQLQWSHGPGPL------PLGALAQGGTLSIPSVQARDSGYYNCTATN 312
Cdd:pfam13927   1 KPVITVSPSSV-TVREGETVTLTCEATGS-PPPTITWYKNGEPIssgstrSRSLSGSNSTLTISNVTRSDAGTYTCVASN 78

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 59.96 E-value: 5.09e-11

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 24111244    49 TIREGDTLMLQCLVTGHPRPQVRWTKtAGS---ASDKFQETSVFNE-TLRIERIARTQGGRYYCKAENGVG 115
Cdd:pfam07679  11 EVQEGESARFTCTVTGTPDPEVSWFK-DGQplrSSDRFKVTYEGGTyTLTISNVQPDDSGKYTCVATNSAG 80

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 58.29 E-value: 1.47e-10

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244     46 RVYTIREGDTLMLQCLVTGHPRPQVRWTKTAG---SASDKFQETSV-FNETLRIERIARTQGGRYYCKAENGVGVpAIKS 121
Cdd:smart00410   2 PSVTVKEGESVTLSCEASGSPPPEVTWYKQGGkllAESGRFSVSRSgSTSTLTISNVTPEDSGTYTCAATNSSGS-ASSG 80


                   ....*
gi 24111244    122 IRVDV 126
Cdd:smart00410  81 TTLTV 85

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 57.13 E-value: 4.47e-10

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244    450 VVTVREGSPAELQCEVRGKPRPPVLWSRVDKEAALLPSGLPLEETP-DGKLRLERVSRDMSGTYRCQtARYNGFNVrprE 528
Cdd:smart00410   3 SVTVKEGESVTLSCEASGSPPPEVTWYKQGGKLLAESGRFSVSRSGsTSTLTISNVTPEDSGTYTCA-ATNSSGSA---S 78


                   ....*..
gi 24111244    529 AQVQLNV 535
Cdd:smart00410  79 SGTTLTV 85

Immunoglobulin (Ig)-like domain found in Perlecan and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain found in Perlecan. Perlecan is a large multi-domain heparin sulfate proteoglycan, important in tissue development and organogenesis. Perlecan can be represented as 5 major portions; its fourth major portion (domain IV) is a tandem repeat of immunoglobulin-like domains (Ig2-Ig15) which can vary in size due to alternative splicing. Perlecan binds many cellular and extracellular ligands. Its domain IV region has many binding sites. Some of these have been mapped at the level of individual Ig-like domains, including a site restricted to the Ig5 domain for heparin/sulfatide, a site restricted to the Ig3 domain for nidogen-1 and nidogen-2, a site restricted to Ig4-5 for fibronectin, and sites restricted to Ig2 and to Ig13-15 for fibulin-2. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409412 Cd Length: 85 Bit Score: 56.80 E-value: 5.24e-10

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 24111244 252 VNPGENVTVQCLLTGGDPLPQLQWSHGPGPLPLGALAQGGTLSIPSVQARDSGYYNCTATNN 313
Cdd:cd05754  13 VRPGADVSFICRAKSKSPAYTLVWTRVNGTLPSRAMDFNGILTIRNVQLSDAGTYVCTGSNM 74

Fifth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409550 [Multi-domain] Cd Length: 89 Bit Score: 56.42 E-value: 6.73e-10

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 239 PPALKLSVNETLVVnpGENVTVQCLLtGGDPLPQLQWSHGPGPLPLG---ALAQGGTLSIPSVQ-ARDSGYYNCTATNNV 314
Cdd:cd20958   1 PPFIRPMGNLTAVA--GQTLRLHCPV-AGYPISSITWEKDGRRLPLNhrqRVFPNGTLVIENVQrSSDEGEYTCTARNQQ 77

                        90
                ....*....|..
gi 24111244 315 GNPAKKTVNLLV 326
Cdd:cd20958  78 GQSASRSVFVKV 89

agrin-responsive first immunoglobulin-like domains (Ig1) of the MuSK ectodomain; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domains (Ig1) of the Muscle-specific kinase (MuSK). MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409562 [Multi-domain] Cd Length: 92 Bit Score: 55.98 E-value: 1.31e-09

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244  49 TIREGDTLMLQCLVTGHPRPQVRWTKTAGS--ASDKFQETSVFNETLRIERIARTQGGRYYCKAENGVGVPAIKSIRVDV 126
Cdd:cd20970  13 TAREGENATFMCRAEGSPEPEISWTRNGNLiiEFNTRYIVRENGTTLTIRNIRRSDMGIYLCIASNGVPGSVEKRITLQV 92

Seventh immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the seventh immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409546 [Multi-domain] Cd Length: 96 Bit Score: 54.63 E-value: 4.28e-09

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244  53 GDTLMLQCLVTGHPRPQVRWTKTAGSASDKFQE------TSVF-NETLRIERIARTQGGRYYCKAENGVG 115
Cdd:cd20954  16 GQDVMLHCQADGFPTPTVTWKKATGSTPGEYKDllydpnVRILpNGTLVFGHVQKENEGHYLCEAKNGIG 85

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 54.12 E-value: 4.32e-09

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244   245 SVNETLVVNPGENVTVQCLLTGGDPLPQLQWSHGPGPLPLGALAQGG-------TLSIPSVQARDSGYYNCTATNNVGNP 317
Cdd:pfam00047   1 SAPPTVTVLEGDSATLTCSASTGSPGPDVTWSKEGGTLIESLKVKHDngrttqsSLLISNVTKEDAGTYTCVVNNPGGSA 80


                  ....
gi 24111244   318 AKKT 321
Cdd:pfam00047  81 TLST 84

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 53.42 E-value: 7.81e-09

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244   334 FQITPDVIKesenIQLGQDLKLSCHVDAVPQEKVTyqWFKNGKPARMSKRLLVTRNDpelpaVTSSLELIDLHFSDYGTY 413
Cdd:pfam07679   3 FTQKPKDVE----VQEGESARFTCTVTGTPDPEVS--WFKDGQPLRSSDRFKVTYEG-----GTYTLTISNVQPDDSGKY 71


                  ....*
gi 24111244   414 LCMAS 418
Cdd:pfam07679  72 TCVAT 76

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 52.72 E-value: 8.63e-09

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 24111244 258 VTVQCLLTGgDPLPQLQWSHGPGPLPLGALAQ------GGTLSIPSVQARDSGYYNCTATNNVGNPAKKTV 322
Cdd:cd00096   1 VTLTCSASG-NPPPTITWYKNGKPLPPSSRDSrrselgNGTLTISNVTLEDSGTYTCVASNSAGGSASASV 70

Third immunoglobulin (Ig) domain of contactin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409357 [Multi-domain] Cd Length: 88 Bit Score: 53.32 E-value: 9.05e-09

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 24111244 240 PALKLSVNETLVVNPGENVTVQCLLTGgDPLPQLQWSHGPGPLPLGA--LAQGGTLSIPSVQARDSGYYNCTATNNVG 315
Cdd:cd04968   1 PSIKVRFPADTYALKGQTVTLECFALG-NPVPQIKWRKVDGSPSSQWeiTTSEPVLEIPNVQFEDEGTYECEAENSRG 77

Sixth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the sixth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409551 Cd Length: 94 Bit Score: 53.27 E-value: 1.20e-08

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 253 NPGENVTVQCLLTGGDPLPQLQWSHGPGPLP--LGAL-----AQGGTLSIPSVQARDSGYYNCTATNNVGNpAKKTVNLL 325
Cdd:cd20959  15 QVGMRAQLHCGVPGGDLPLNIRWTLDGQPISddLGITvsrlgRRSSILSIDSLEASHAGNYTCHARNSAGS-ASYTAPLT 93


                .
gi 24111244 326 V 326
Cdd:cd20959  94 V 94

agrin-responsive first immunoglobulin-like domains (Ig1) of the MuSK ectodomain; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domains (Ig1) of the Muscle-specific kinase (MuSK). MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409562 [Multi-domain] Cd Length: 92 Bit Score: 52.90 E-value: 1.47e-08

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 248 ETLVVNPGENVTVQCLLTGgDPLPQLQWSHGPGPLPLGA-----LAQGGTLSIPSVQARDSGYYNCTATNNVGNPAKKTV 322
Cdd:cd20970  10 FTVTAREGENATFMCRAEG-SPEPEISWTRNGNLIIEFNtryivRENGTTLTIRNIRRSDMGIYLCIASNGVPGSVEKRI 88


                ....
gi 24111244 323 NLLV 326
Cdd:cd20970  89 TLQV 92

Third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409390 [Multi-domain] Cd Length: 83 Bit Score: 52.40 E-value: 1.65e-08

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 24111244 251 VVNPGENVTVQCLLtGGDPLPQLQWSHGPGPLPLGALAQ--GGTLSIPSVQARDSGYYNCTATNNVG 315
Cdd:cd05725   8 VVLVDDSAEFQCEV-GGDPVPTVRWRKEDGELPKGRYEIldDHSLKIRKVTAGDMGSYTCVAENMVG 73

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 51.49 E-value: 4.62e-08

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244   250 LVVNPGENVTVQCLLTGgDPLPQLQWSHGPGPLPLG------ALAQGGTLSIPSVQARDSGYYNCTATNNVGNpAKKTVN 323
Cdd:pfam07679  10 VEVQEGESARFTCTVTG-TPDPEVSWFKDGQPLRSSdrfkvtYEGGTYTLTISNVQPDDSGKYTCVATNSAGE-AEASAE 87


                  ...
gi 24111244   324 LLV 326
Cdd:pfam07679  88 LTV 90

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM); The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains, five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM.

Pssm-ID: 409460 [Multi-domain] Cd Length: 83 Bit Score: 51.07 E-value: 4.69e-08

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 24111244  48 YTIREGDTLMLQCLVTGHPRPQVRWTKTAGSASDKFQETSVFNETLRIERIARTQGGRYYCKAENGVG 115
Cdd:cd05876   5 LVALRGQSLVLECIAEGLPTPTVKWLRPSGPLPPDRVKYQNHNKTLQLLNVGESDDGEYVCLAENSLG 72

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 50.79 E-value: 4.83e-08

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244  56 LMLQCLVTGHPRPQVRWTKTAGSASDKFQETSVF---NETLRIERIARTQGGRYYCKAENGVGVPAIKSI 122
Cdd:cd00096   1 VTLTCSASGNPPPTITWYKNGKPLPPSSRDSRRSelgNGTLTISNVTLEDSGTYTCVASNSAGGSASASV 70

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 50.79 E-value: 4.83e-08

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*..
gi 24111244 459 AELQCEVRGKPRPPVLWSRVDKEAALLPSGLPLEETPDGKLRLERVSRDMSGTYRCQ 515
Cdd:cd00096   1 VTLTCSASGNPPPTITWYKNGKPLPPSSRDSRRSELGNGTLTISNVTLEDSGTYTCV 57

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 50.97 E-value: 5.89e-08

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 24111244    152 TVFLRCTVNSNPPARFIWKRGSDTLSHSQDNGVdiyepLYTQGETKVLKLKNLRPQDYASYTCQVS 217
Cdd:smart00410  11 SVTLSCEASGSPPPEVTWYKQGGKLLAESGRFS-----VSRSGSTSTLTISNVTPEDSGTYTCAAT 71

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 50.97 E-value: 6.19e-08

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 24111244    343 ESENIQLGQDLKLSCHVDAVPQEKVTyqWFKNG-KPARMSKRLLVTRNDPelpavTSSLELIDLHFSDYGTYLCMAS 418
Cdd:smart00410   2 PSVTVKEGESVTLSCEASGSPPPEVT--WYKQGgKLLAESGRFSVSRSGS-----TSTLTISNVTPEDSGTYTCAAT 71

Third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409390 [Multi-domain] Cd Length: 83 Bit Score: 50.47 E-value: 7.71e-08

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 24111244 451 VTVREGSPAELQCEVRGKPRPPVLWSRVDKEaalLPSGlPLEETPDGKLRLERVSRDMSGTYRCQ 515
Cdd:cd05725   7 QVVLVDDSAEFQCEVGGDPVPTVRWRKEDGE---LPKG-RYEILDDHSLKIRKVTAGDMGSYTCV 67

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 49.64 E-value: 1.38e-07

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 24111244 153 VFLRCTVNSNPPARFIWKRGSDTLSHSQdngvdiYEPLYTQGETKVLKLKNLRPQDYASYTCQVS 217
Cdd:cd00096   1 VTLTCSASGNPPPTITWYKNGKPLPPSS------RDSRRSELGNGTLTISNVTLEDSGTYTCVAS 59

Third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409390 [Multi-domain] Cd Length: 83 Bit Score: 49.32 E-value: 1.99e-07

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 24111244  53 GDTLMLQCLVTGHPRPQVRWTKTAGSASDKFQETsVFNETLRIERIARTQGGRYYCKAENGVG 115
Cdd:cd05725  12 DDSAEFQCEVGGDPVPTVRWRKEDGELPKGRYEI-LDDHSLKIRKVTAGDMGSYTCVAENMVG 73

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 49.10 E-value: 2.04e-07

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 24111244   342 KESENIQLGQDLKLSCHVDAVPqeKVTYQWFKNGKPARMSKRLLVTRNDpelpaVTSSLELIDLHFSDYGTYLCMAS 418
Cdd:pfam13927   8 PSSVTVREGETVTLTCEATGSP--PPTITWYKNGEPISSGSTRSRSLSG-----SNSTLTISNVTRSDAGTYTCVAS 77

Third immunoglobulin (Ig) domain of contactin-1; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 143259 Cd Length: 88 Bit Score: 49.63 E-value: 2.04e-07

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 24111244 239 PPALKLSVNETLVVNpGENVTVQCLLTGgDPLPQLQWSHGPGPLPLGA--LAQGGTLSIPSVQARDSGYYNCTATNNVG 315
Cdd:cd05851   1 PADINVKFKDTYALK-GQNVTLECFALG-NPVPVIRWRKILEPMPATAeiSMSGAVLKIFNIQPEDEGTYECEAENIKG 77

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 49.10 E-value: 2.10e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244   132 PMLTVHQTVSDVRGNfyqeKTVFLRCTVNSNPPARFIWKRGSDTLSHSQDngvdiyEPLYTQGETKVLKLKNLRPQDYAS 211
Cdd:pfam13927   2 PVITVSPSSVTVREG----ETVTLTCEATGSPPPTITWYKNGEPISSGST------RSRSLSGSNSTLTISNVTRSDAGT 71


                  ....*.
gi 24111244   212 YTCQVS 217
Cdd:pfam13927  72 YTCVAS 77

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

Pssm-ID: 464026 [Multi-domain] Cd Length: 79 Bit Score: 48.93 E-value: 2.47e-07

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244   241 ALKLSVNETlVVNPGENVTVQCLLtGGDPLPQLQWSHGPGPLPlgalaQGGTLSIPSVQARDSGYYNCTATNNVGNPAKK 320
Cdd:pfam13895   1 KPVLTPSPT-VVTEGEPVTLTCSA-PGNPPPSYTWYKDGSAIS-----SSPNFFTLSVSAEDSGTYTCVARNGRGGKVSN 73


                  ....*.
gi 24111244   321 TVNLLV 326
Cdd:pfam13895  74 PVELTV 79

Immunoglobulin I-set domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1); The members here are composed of the immunoglobulin I-set (IgI) domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1). Human Lingo-1 is a central nervous system-specific transmembrane glycoprotein also known as LERN-1, which functions as a negative regulator of neuronal survival, axonal regeneration, and oligodendrocyte differentiation and myelination. Lingo-1 is a key component of the Nogo receptor signaling complex (RTN4R/NGFR) in RhoA activation responsible for some inhibition of axonal regeneration by myelin-associated factors. The ligand-binding ectodomain of human Lingo-1 contains a bimodular, kinked structure composed of leucine-rich repeat (LRR) and immunoglobulin (Ig)-like modules. Diseases associated with Lingo-1 include mental retardation, autosomal recessive 64 and essential tremor. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the Lingo-1 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409561 Cd Length: 92 Bit Score: 49.31 E-value: 2.88e-07

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 239 PPALKLSVNETLVVNPGENVTVQCLlTGGDPLPQLQWSHgPGPLPLGALAQG-------GTLSIPSVQARDSGYYNCTAT 311
Cdd:cd20969   1 RAAIRDRKAQQVFVDEGHTVQFVCR-ADGDPPPAILWLS-PRKHLVSAKSNGrltvfpdGTLEVRYAQVQDNGTYLCIAA 78

                        90
                ....*....|....*
gi 24111244 312 NNVGNpAKKTVNLLV 326
Cdd:cd20969  79 NAGGN-DSMPAHLHV 92

Third immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the third immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143222 [Multi-domain] Cd Length: 74 Bit Score: 47.63 E-value: 5.97e-07

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 24111244  52 EGDTLMLQCLVTGHPRPQVRWTKTAGSASDKFQETSVFNETLRIERIARTQGGRYYCKAENGVG 115
Cdd:cd05745   1 EGQTVDFLCEAQGYPQPVIAWTKGGSQLSVDRRHLVLSSGTLRISRVALHDQGQYECQAVNIVG 64

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 48.02 E-value: 7.31e-07

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 24111244   451 VTVREGSPAELQCEVRGKPRPPVLWSRVDKEAALLPSGLPLEETPDGKLRLERVSRDMSGTYRCQ 515
Cdd:pfam07679  10 VEVQEGESARFTCTVTGTPDPEVSWFKDGQPLRSSDRFKVTYEGGTYTLTISNVQPDDSGKYTCV 74

Fourth Ig domain of the neural cell adhesion molecule contactin-2, and similar domains; The members here are composed of the fourth Ig domain of the neural cell adhesion molecule contactin-2. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (also called TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. The first four Ig domains form the intermolecular binding fragment which arranges as a compact U-shaped module by contacts between Ig domains 1 and 4, and domains 2 and 3. It has been proposed that a linear zipper-like array forms, from contactin-2 molecules alternatively provided by the two apposed membranes.

Pssm-ID: 143205 [Multi-domain] Cd Length: 85 Bit Score: 47.98 E-value: 7.36e-07

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244  53 GDTLMLQCLVTGHPRPQVRWTKTaGSASDKFQETSVFNETLRIERIARTQGGRYYCKAEN 112
Cdd:cd05728  14 GSSLRWECKASGNPRPAYRWLKN-GQPLASENRIEVEAGDLRITKLSLSDSGMYQCVAEN 72

Fourth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409548 [Multi-domain] Cd Length: 96 Bit Score: 47.94 E-value: 8.17e-07

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 239 PPALKLSVNEtLVVNPGENVTVQCLLTGgDPLPQLQWSHGPGPLPLGALAQGGT-----------LSIPSVQARDSGYYN 307
Cdd:cd20956   1 APVLLETFSE-QTLQPGPSVSLKCVASG-NPLPQITWTLDGFPIPESPRFRVGDyvtsdgdvvsyVNISSVRVEDGGEYT 78


                ....*...
gi 24111244 308 CTATNNVG 315
Cdd:cd20956  79 CTATNDVG 86

Fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related); The members here are composed of the fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related). These proteins belong to the L1 subfamily of cell adhesion molecules (CAMs) and are comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. These molecules are primarily expressed in the nervous system. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth.

Pssm-ID: 409367 [Multi-domain] Cd Length: 89 Bit Score: 47.44 E-value: 1.01e-06

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 250 LVVNPGENVTVQCLlTGGDPLPQLQWS-HG----PGPLPLGALAQGGTLSIPSVQARDSGYYNCTATnNVGNPAKKTVNL 324
Cdd:cd04978   9 LVLSPGETGELICE-AEGNPQPTITWRlNGvpiePAPEDMRRTVDGRTLIFSNLQPNDTAVYQCNAS-NVHGYLLANAFL 86


                ...
gi 24111244 325 LVR 327
Cdd:cd04978  87 HVL 89

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409570 [Multi-domain] Cd Length: 88 Bit Score: 47.39 E-value: 1.18e-06

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 24111244 250 LVVNPGENVTVQCLLTGgDPLPQLQWSHGPGPL---PLGALAQGGTLSIPSVQARDSGYYNCTATNNVG 315
Cdd:cd20978  11 VVVKGGQDVTLPCQVTG-VPQPKITWLHNGKPLqgpMERATVEDGTLTIINVQPEDTGYYGCVATNEIG 78

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 47.18 E-value: 1.20e-06

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244   538 PPEVEPSSQDVRQALGRPVLLRCSLlRGSPQriaSAVWRFKGQLLPPPPVVPAAAEAPDHAELRLDAVTRDSSGSYECSV 617
Cdd:pfam13927   1 KPVITVSPSSVTVREGETVTLTCEA-TGSPP---PTITWYKNGEPISSGSTRSRSLSGSNSTLTISNVTRSDAGTYTCVA 76


                  ..
gi 24111244   618 SN 619
Cdd:pfam13927  77 SN 78

agrin-responsive second immunoglobulin-like domains (Ig2) of the Muscle-specific kinase (MuSK) ectodomain; a member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin-like (Ig) domains of the Muscle-specific kinase (MuSK) ectodomain. MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409560 [Multi-domain] Cd Length: 88 Bit Score: 46.85 E-value: 1.75e-06

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 24111244  49 TIREGDTLMLQCLVTGHPRPQVRWTKTAGSASDKFQETSVFNETLRIERIARTQGGRYYCKAENGVGVPAIKSIRVDVQ 127
Cdd:cd20968  10 TIIEGLKAVLPCTTMGNPKPSVSWIKGDDLIKENNRIAVLESGSLRIHNVQKEDAGQYRCVAKNSLGIAYSKPVTIEVE 88

Third immunoglobulin (Ig) domain of contactin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409357 [Multi-domain] Cd Length: 88 Bit Score: 46.39 E-value: 2.56e-06

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 24111244  45 ERVYTIReGDTLMLQCLVTGHPRPQVRWTKTAGSASDKFQETSVfNETLRIERIARTQGGRYYCKAENGVG 115
Cdd:cd04968   9 ADTYALK-GQTVTLECFALGNPVPQIKWRKVDGSPSSQWEITTS-EPVLEIPNVQFEDEGTYECEAENSRG 77

Fourth Ig-like domain from smooth muscle myosin light chain kinase and similar domains ; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain from smooth muscle myosin light chain kinase (MYLK) and similar domains. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of this group shows that the fourth Ig-like domain from myosin light chain kinase lacks this strand and thus belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409568 [Multi-domain] Cd Length: 90 Bit Score: 46.09 E-value: 3.20e-06

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 439 PPTISVPKGRAVVtvrEGSPAELQCEVRGKPRPPVLWSRVdkeaallpsGLPLEETPD--------GKLRLERVSRDMSG 510
Cdd:cd20976   2 PSFSSVPKDLEAV---EGQDFVAQCSARGKPVPRITWIRN---------AQPLQYAADrstceagvGELHIQDVLPEDHG 69


                ....
gi 24111244 511 TYRC 514
Cdd:cd20976  70 TYTC 73

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 45.40 E-value: 4.34e-06

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 24111244 353 LKLSCHVDAVPqeKVTYQWFKNGKPARMSKRLLVTRNDPelpavTSSLELIDLHFSDYGTYLCMASFP 420
Cdd:cd00096   1 VTLTCSASGNP--PPTITWYKNGKPLPPSSRDSRRSELG-----NGTLTISNVTLEDSGTYTCVASNS 61

Immunoglobulin I-set domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1); The members here are composed of the immunoglobulin I-set (IgI) domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1). Human Lingo-1 is a central nervous system-specific transmembrane glycoprotein also known as LERN-1, which functions as a negative regulator of neuronal survival, axonal regeneration, and oligodendrocyte differentiation and myelination. Lingo-1 is a key component of the Nogo receptor signaling complex (RTN4R/NGFR) in RhoA activation responsible for some inhibition of axonal regeneration by myelin-associated factors. The ligand-binding ectodomain of human Lingo-1 contains a bimodular, kinked structure composed of leucine-rich repeat (LRR) and immunoglobulin (Ig)-like modules. Diseases associated with Lingo-1 include mental retardation, autosomal recessive 64 and essential tremor. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the Lingo-1 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409561 Cd Length: 92 Bit Score: 45.84 E-value: 4.88e-06

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 445 PKGRAVVTVREGSPAELQCEVRGKPRPPVLWSRVDKEAALLPSGLPLEETPDGKLRLERVSRDMSGTYRCQTARYNGFNV 524
Cdd:cd20969   6 DRKAQQVFVDEGHTVQFVCRADGDPPPAILWLSPRKHLVSAKSNGRLTVFPDGTLEVRYAQVQDNGTYLCIAANAGGNDS 85


                ....*..
gi 24111244 525 RPREAQV 531
Cdd:cd20969  86 MPAHLHV 92

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

Pssm-ID: 409544 [Multi-domain] Cd Length: 87 Bit Score: 45.57 E-value: 5.22e-06

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 24111244 245 SVNETLVVnpGENVTVQCLLTGgDPLPQLQWSHGPGPLPLG----ALAQGGTLSIPSVQARDSGYYNCTATNNVG 315
Cdd:cd20952   6 PQNQTVAV--GGTVVLNCQATG-EPVPTISWLKDGVPLLGKderiTTLENGSLQIKGAEKSDTGEYTCVALNLSG 77

Second immunoglobulin (Ig)-like domain of protein tyrosine kinase (PTK) 7; The members here are composed of the second immunoglobulin (Ig)-like domain in protein tyrosine kinase (PTK) 7, also known as CCK4. PTK7 is a subfamily of the receptor protein tyrosine kinase family, and is referred to as an RPTK-like molecule. RPTKs transduce extracellular signals across the cell membrane and play important roles in regulating cell proliferation, migration, and differentiation. PTK7 is organized as an extracellular portion having seven Ig-like domains, a single transmembrane region, and a cytoplasmic tyrosine kinase-like domain. PTK7 is considered a pseudokinase as it has several unusual residues in some of the highly conserved tyrosine kinase (TK) motifs; it is predicted to lack TK activity. PTK7 may function as a cell-adhesion molecule. PTK7 mRNA is expressed at high levels in placenta, melanocytes, liver, lung, pancreas, and kidney. PTK7 is overexpressed in several cancers, including melanoma and colon cancer lines.

Pssm-ID: 409417 Cd Length: 95 Bit Score: 45.69 E-value: 6.14e-06

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 24111244  50 IREGDTLMLQCLVTGHPRPQVRWTKTAGSASDKFQETSVFNE--TLRIERIARTQGGRYYCKAENGVG 115
Cdd:cd05760  13 IQPSSRVTLRCHIDGHPRPTYQWFRDGTPLSDGQGNYSVSSKerTLTLRSAGPDDSGLYYCCAHNAFG 80

agrin-responsive first immunoglobulin-like domains (Ig1) of the MuSK ectodomain; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domains (Ig1) of the Muscle-specific kinase (MuSK). MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409562 [Multi-domain] Cd Length: 92 Bit Score: 45.58 E-value: 6.35e-06

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 24111244 440 PTISVPKGRAVVTVREGSPAELQCEVRGKPRPPVLWSRVDKEAALLPSGLPLEEtpDGK-LRLERVSRDMSGTYRC 514
Cdd:cd20970   1 PVISTPQPSFTVTAREGENATFMCRAEGSPEPEISWTRNGNLIIEFNTRYIVRE--NGTtLTIRNIRRSDMGIYLC 74

Fourth immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM); The members here are composed of the fourth immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region, and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM.

Pssm-ID: 409453 [Multi-domain] Cd Length: 89 Bit Score: 45.27 E-value: 6.78e-06

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 24111244 248 ETLVVNPGENVTVQCLLtGGDPLPQLQWS-HGpgpLPLGALA-------QGGTLSIPSVQARDSGYYNCTATNNVGN 316
Cdd:cd05867   7 QSHLYGPGETARLDCQV-EGIPTPNITWSiNG---APIEGTDpdprrhvSSGALILTDVQPSDTAVYQCEARNRHGN 79

CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold domain; CD19, also known as B-Lymphocyte Surface Antigen B4, T-Cell Surface Antigen Leu-12, and CVID3, is a transmembrane receptor present on various types of B cells, including progenitor, naive, and memory B cells, as well as plasmablasts. Until recently, it was believed to comprise two extracellular immunoglobulin (Ig) structural domains arranged in tandem with C2 topology. However, recent crystal structures have shown that the CD19 extracellular domain contains a unique double Ig domain that is responsible for its binding to proteins such as CD21, CD81, and CD225, which regulate B cell activation and survival. A recent analysis of the CD19 extracellular domain sequence reveals two "Ig domains", but the structure demonstrates that these two domains are not folded independently and connected in tandem. Rather, they fold together as one intertwined domain that can be referred to as a "double Ig" domain. Each of the two regular Ig domain sequences has a noticeably short linker that forms a loop between strands C' and D, rather than allowing the formation of a C" strand. Additionally, the two Ig-domain sequences are separated by a long linker that is structured as a small insertion domain, enabling both Ig sequences to fold together as a unique double Ig-domain. The CD19 domain comprises four "protodomains": two formed by A'B-CC' strands and two by DE-FG strands that interdigitate to form a novel double Ig fold. When analyzing this double Ig domain in terms of the usual Ig-fold, A'B-CC' protodomain of the first Ig sequence combines with DE-FG protodomain of the second, and vice versa. Hence, the second combined Ig fold is inverted, with DE-FG protodomain of the first Ig sequence combining with A'B-CC' protodomain of the second Ig sequence and in that order, as if it were a circular permutation, obtained only through structural folding.

Pssm-ID: 467824 Cd Length: 89 Bit Score: 45.02 E-value: 6.97e-06

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 24111244 451 VTVREGSPAELQCEV--RGKPRPPVLWSRVDKEAALLP-----SGLPLEETPDGK-LRLERVSRDMSGTYRCQ 515
Cdd:cd23997   3 VTVAEGSTLWLPCLVppSDGPRGPLTWSRGHPKTPLLSlelgsPGLWVLVGPLGIlLLLPNVSAQMGGFYLCE 75

Immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM); The members here are composed of the immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM). DSCAM is a cell adhesion molecule expressed largely in the developing nervous system. The gene encoding DSCAM is located at human chromosome 21q22, the locus associated with the intellectual disability phenotype of Down Syndrome. DSCAM is predicted to be the largest member of the IG superfamily. It has been demonstrated that DSCAM can mediate cation-independent homophilic intercellular adhesion.

Pssm-ID: 409397 [Multi-domain] Cd Length: 97 Bit Score: 45.18 E-value: 7.84e-06

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244  53 GDTLMLQCLVTGHPRPQVRWTKTAGSASDKFQETSVF--------NETLRIERIARTQGGRYYCKAENGVGVPAIKSIRV 124
Cdd:cd05734  16 GKAVVLNCSADGYPPPTIVWKHSKGSGVPQFQHIVPLngriqllsNGSLLIKHVLEEDSGYYLCKVSNDVGADISKSMYL 95


                ..
gi 24111244 125 DV 126
Cdd:cd05734  96 TV 97

Immunoglobulin (Ig)-like domain of titin and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain found in titin-like proteins and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is a giant protein; depending on isoform composition, it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone. It appears to function similarly to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. Within the sarcomere, titin is also attached to or is associated with myosin binding protein C (MyBP-C). MyBP-C appears to contribute to the generation of passive tension by titin and like titin has repeated Ig-like and FN-III domains. Also included in this group are worm twitchin and insect projectin, thick filament proteins of invertebrate muscle which also have repeated Ig-like and FN-III domains.

Pssm-ID: 409406 [Multi-domain] Cd Length: 82 Bit Score: 44.50 E-value: 9.10e-06

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244  47 VYTIREGDTLMLQCLVTGHPRPQVRWTK--TAGSASDKFQ-ETSVFNETLRIERIARTQGGRYYCKAENGVGvPAIKSIR 123
Cdd:cd05748   1 TIVVRAGESLRLDIPIKGRPTPTVTWSKdgQPLKETGRVQiETTASSTSLVIKNAKRSDSGKYTLTLKNSAG-EKSATIN 79


                ...
gi 24111244 124 VDV 126
Cdd:cd05748  80 VKV 82

First Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409566 [Multi-domain] Cd Length: 93 Bit Score: 44.65 E-value: 1.11e-05

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 24111244  50 IREGDTLMLQCLVTGHPRPQVRWTK----TAGSASDKFQ-ETSVFNETLRIERIARTQGGRYYCKAENGVG 115
Cdd:cd20974  12 VLEGSTATFEAHVSGKPVPEVSWFRdgqvISTSTLPGVQiSFSDGRAKLSIPAVTKANSGRYSLTATNGSG 82

Immunoglobulin (Ig)-like domain of human titin C terminus and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain from the C-terminus of human titin x and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is gigantic; depending on isoform composition it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone and appears to function similar to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 143224 [Multi-domain] Cd Length: 92 Bit Score: 44.65 E-value: 1.19e-05

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 24111244  46 RVYTIREGDTLMLQCLVTGHPRPQVRWTKTAG--SASDKFQETSV-FNETLRIERIARTQGGRYYCKAENGVG 115
Cdd:cd05747  11 RSLTVSEGESARFSCDVDGEPAPTVTWMREGQiiVSSQRHQITSTeYKSTFEISKVQMSDEGNYTVVVENSEG 83

Immunoglobulin (Ig)-like ectodomain of the LRIG1 (Leucine-rich Repeats And Immunoglobulin-like Domains Protein 1) and similar proteins; member of the I-set of IgSF domains; The members here are composed of subgroup of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. The ectodomain of LRIG1 has two distinct regions: the proposed 15 LRRs and three Ig-like domains closer to the membrane. LRIG1 has been reported to interact with many receptor tyrosine kinases, GDNF/c-Ret, E-cadherin, JAK/STAT, c-Met, and the EGFR family signaling systems. Immunoglobulin Superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The structure of the LRIG1 extracellular Ig domain lacks a C" strand and thus is better described as a member of the I-set of IgSF domains.

Pssm-ID: 409420 [Multi-domain] Cd Length: 91 Bit Score: 44.53 E-value: 1.25e-05

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 24111244  49 TIREGDTLMLQCLVTGHPRPQVRWTKTAG----SASDKFQETSVFNETLRIERIARTQGGRYYCKAENGVG 115
Cdd:cd05763  10 TIRAGSTARLECAATGHPTPQIAWQKDGGtdfpAARERRMHVMPEDDVFFIVDVKIEDTGVYSCTAQNSAG 80

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM), and similar domains; The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM and human neurofascin.

Pssm-ID: 409394 [Multi-domain] Cd Length: 83 Bit Score: 44.32 E-value: 1.37e-05

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 249 TLVVNPGENVTVQCLlTGGDPLPQLQWSHGPGPLPLGALAQ---GGTLSIPSVQARDSGYYNCTATNNVGNpAKKTVNLL 325
Cdd:cd05731   4 STMVLRGGVLLLECI-AEGLPTPDIRWIKLGGELPKGRTKFenfNKTLKIENVSEADSGEYQCTASNTMGS-ARHTISVT 81


                ..
gi 24111244 326 VR 327
Cdd:cd05731  82 VE 83

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409570 [Multi-domain] Cd Length: 88 Bit Score: 44.31 E-value: 1.53e-05

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 338 PDVIKESEN---IQLGQDLKLSCHVDAVPQEKVTyqWFKNGKP-ARMSKRLLVTRNdpelpavtsSLELIDLHFSDYGTY 413
Cdd:cd20978   1 PKFIQKPEKnvvVKGGQDVTLPCQVTGVPQPKIT--WLHNGKPlQGPMERATVEDG---------TLTIINVQPEDTGYY 69


                ....*
gi 24111244 414 LCMAS 418
Cdd:cd20978  70 GCVAT 74

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409549 [Multi-domain] Cd Length: 88 Bit Score: 44.06 E-value: 1.71e-05

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 24111244 449 AVVTVREGSPAELQCEVRGKPRPPVLWSrvdKEAALLPSGLPLEETPDGKLRLERVSRDMSGTYRC 514
Cdd:cd20957   9 PVQTVDFGRTAVFNCSVTGNPIHTVLWM---KDGKPLGHSSRVQILSEDVLVIPSVKREDKGMYQC 71

Third immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the third immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143222 [Multi-domain] Cd Length: 74 Bit Score: 43.77 E-value: 1.84e-05

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 24111244 255 GENVTVQCLlTGGDPLPQLQWSHGPGPLPLG---ALAQGGTLSIPSVQARDSGYYNCTATNNVGnpAKKTVNLLV 326
Cdd:cd05745   2 GQTVDFLCE-AQGYPQPVIAWTKGGSQLSVDrrhLVLSSGTLRISRVALHDQGQYECQAVNIVG--SQRTVAQLT 73

Fifth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409550 [Multi-domain] Cd Length: 89 Bit Score: 43.71 E-value: 2.46e-05

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244  49 TIREGDTLMLQCLVTGHPRPQVRWTKtAGSASDKFQETSVF-NETLRIERIARTQ-GGRYYCKAENGVGVPAIKSIRVDV 126
Cdd:cd20958  11 TAVAGQTLRLHCPVAGYPISSITWEK-DGRRLPLNHRQRVFpNGTLVIENVQRSSdEGEYTCTARNQQGQSASRSVFVKV 89

Immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM); The members here are composed of the immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM). DSCAM is a cell adhesion molecule expressed largely in the developing nervous system. The gene encoding DSCAM is located at human chromosome 21q22, the locus associated with the intellectual disability phenotype of Down Syndrome. DSCAM is predicted to be the largest member of the IG superfamily. It has been demonstrated that DSCAM can mediate cation-independent homophilic intercellular adhesion.

Pssm-ID: 409397 [Multi-domain] Cd Length: 97 Bit Score: 44.02 E-value: 2.48e-05

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 255 GENVTVQCLLTGgDPLPQLQWSHGPG--------PLPLGALAQ---GGTLSIPSVQARDSGYYNCTATNNVGNPAKKTVN 323
Cdd:cd05734  16 GKAVVLNCSADG-YPPPTIVWKHSKGsgvpqfqhIVPLNGRIQllsNGSLLIKHVLEEDSGYYLCKVSNDVGADISKSMY 94


                ...
gi 24111244 324 LLV 326
Cdd:cd05734  95 LTV 97

Immunoglobulin (Ig)-like domain of the human basement membrane heparan sulfate proteoglycan perlecan and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain of the human basement membrane heparan sulfate proteoglycan perlecan, also known as HSPG2, and similar proteins. Perlecan consists of five domains: domain I has three putative heparan sulfate attachment sites, domain II has four LDL receptor-like repeats, and one Ig-like repeat, domain III resembles the short arm of laminin chains, domain IV has multiple Ig-like repeats (21 repeats in human perlecan), and domain V resembles the globular G domain of the laminin A chain and internal repeats of EGF. Perlecan may participate in a variety of biological functions including cell binding, LDL-metabolism, basement membrane assembly and selective permeability, calcium binding, and growth- and neurite-promoting activities.

Pssm-ID: 143220 Cd Length: 78 Bit Score: 43.25 E-value: 2.66e-05

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 24111244 255 GENVTVQCLLTGgDPLP----QLQWSHGPGPLPLGALAQGG--TLSIPSVQARDSGYYNCTATNNVG 315
Cdd:cd05743   1 GETVEFTCVATG-VPTPiinwRLNWGHVPDSARVSITSEGGygTLTIRDVKESDQGAYTCEAINTRG 66

Second immunoglobulin (Ig)-like domain of a Follistatin-related protein 5, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in human Follistatin-related protein 5 (FSTL5) and a follistatin-like molecule encoded by the CNS-related Mahya gene. Mahya genes have been retained in certain Bilaterian branches during evolution. They are conserved in Hymenoptera and Deuterostomes, but are absent from other metazoan species such as fruit fly and nematode. Mahya proteins are secretory, with a follistatin-like domain (Kazal-type serine/threonine protease inhibitor domain and EF-hand calcium-binding domain), two Ig-like domains, and a novel C-terminal domain. Mahya may be involved in learning and memory and in processing of sensory information in Hymenoptera and vertebrates. Follistatin is a secreted, multidomain protein that binds activins with high affinity and antagonizes their signaling.

Pssm-ID: 409399 [Multi-domain] Cd Length: 93 Bit Score: 43.40 E-value: 3.02e-05

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 340 VIKESENIQLGQDLKLSCHVDAVPQEKVtyQWFKNGKP--ARMSKRLlvtrndpELPAVTSSLELIDLHFSDYGTYLCMA 417
Cdd:cd05736   5 VYPEFQAKEPGVEASLRCHAEGIPLPRV--QWLKNGMDinPKLSKQL-------TLIANGSELHISNVRYEDTGAYTCIA 75

                        90
                ....*....|.
gi 24111244 418 SFPGAPVPDLS 428
Cdd:cd05736  76 KNEGGVDEDIS 86

Fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; Members here are composed the fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1, Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409391 [Multi-domain] Cd Length: 98 Bit Score: 43.79 E-value: 3.05e-05

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 452 TVREGSPAELQCEVRGKPRPPVLWSRVDKEAALLPSGLP-----LEETPDGKLRLERVSRDMSGTYRCQT 516
Cdd:cd05726  10 VVALGRTVTFQCETKGNPQPAIFWQKEGSQNLLFPYQPPqpssrFSVSPTGDLTITNVQRSDVGYYICQA 79

Fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; Members here are composed the fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1, Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409391 [Multi-domain] Cd Length: 98 Bit Score: 43.79 E-value: 3.17e-05

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 24111244 251 VVNPGENVTVQCLlTGGDPLPQLQW-----------SHGPGPLPLGALAQGGTLSIPSVQARDSGYYNCTATNNVGN 316
Cdd:cd05726  10 VVALGRTVTFQCE-TKGNPQPAIFWqkegsqnllfpYQPPQPSSRFSVSPTGDLTITNVQRSDVGYYICQALNVAGS 85

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409389 [Multi-domain] Cd Length: 87 Bit Score: 42.77 E-value: 4.89e-05

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 541 VEPSsqDVRQALGRPVLLRCSLLRGSPQRIASavWRFKGQLLpppPVVPAAAEAPDHAELRLDAVTRDSSGSYECSVSND 620
Cdd:cd05724   2 VEPS--DTQVAVGEMAVLECSPPRGHPEPTVS--WRKDGQPL---NLDNERVRIVDDGNLLIAEARKSDEGTYKCVATNM 74


                ..
gi 24111244 621 VG 622
Cdd:cd05724  75 VG 76

Second Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409564 [Multi-domain] Cd Length: 91 Bit Score: 42.96 E-value: 5.45e-05

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 24111244  46 RVYTIREGDTLMLQCLVTGHPRPQVRWTKTaGSASDKFQETSVFNE----TLRIERIARTQGGRYYCKAENGVG 115
Cdd:cd20972   9 RSQEVAEGSKVRLECRVTGNPTPVVRWFCE-GKELQNSPDIQIHQEgdlhSLIIAEAFEEDTGRYSCLATNSVG 81

C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin, and similar domains; member of the I-set IgSF domains; The members here are composed of the C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin and similar proteins, including Caenorhabditis elegans and Aplysia californica Twitchin, Drosophila melanogaster Projectin, and similar proteins. These are very large muscle proteins containing multiple immunoglobulin (Ig)-like and fibronectin type III (FN3) domains and a single kinase domain near the C-terminus. In humans these proteins are called Titin. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig-like domain of the Twitchin is a member of the I-set IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins (titin, telokin, and twitchin), the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D.

Pssm-ID: 409541 [Multi-domain] Cd Length: 89 Bit Score: 42.70 E-value: 5.48e-05

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 24111244 450 VVTVREGSPAELQCEVRGKPRPPVLWSRVDKEAALLPSGLPLEETPDGKLRLERVSRDMSGTYRCQTARYNG 521
Cdd:cd20949   8 VTTVKEGQSATILCEVKGEPQPNVTWHFNGQPISASVADMSKYRILADGLLINKVTQDDTGEYTCRAYQVNS 79

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM), and similar domains; The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM and human neurofascin.

Pssm-ID: 409394 [Multi-domain] Cd Length: 83 Bit Score: 42.01 E-value: 7.77e-05

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 24111244 451 VTVREGSPAELQCEVRGKPRPPVLWSRVDKEaalLPSGLPLEETPDGKLRLERVSRDMSGTYRCqTAR 518
Cdd:cd05731   5 TMVLRGGVLLLECIAEGLPTPDIRWIKLGGE---LPKGRTKFENFNKTLKIENVSEADSGEYQC-TAS 68

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM); The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains, five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM.

Pssm-ID: 409460 [Multi-domain] Cd Length: 83 Bit Score: 41.82 E-value: 8.34e-05

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 249 TLVVNPGENVTVQCLlTGGDPLPQLQWSHGPGPLP---LGALAQGGTLSIPSVQARDSGYYNCTATNNVG 315
Cdd:cd05876   4 SLVALRGQSLVLECI-AEGLPTPTVKWLRPSGPLPpdrVKYQNHNKTLQLLNVGESDDGEYVCLAENSLG 72

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor_like-1(FGFRL1); member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 is comprised of a signal peptide, three extracellular Ig-like modules, a transmembrane segment, and a short intracellular domain. FGFRL1 is expressed preferentially in skeletal tissues. Similar to FGF receptors, the expressed protein interacts specifically with heparin and with FGF2. FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409442 Cd Length: 92 Bit Score: 42.15 E-value: 8.35e-05

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 24111244 152 TVFLRCTVNSNPPARFIWKRGSDTLshsqdngvDIYEPLYTQGETKVLKLKNLRPQDYASYTCQVSVR 219
Cdd:cd05856  21 SVRLKCVASGNPRPDITWLKDNKPL--------TPPEIGENKKKKWTLSLKNLKPEDSGKYTCHVSNR 80

Immunoglobulin domain I1 of the titin I-band and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin domain I1 of the titin I-band and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig I1 domain of the titin I-band is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409543 [Multi-domain] Cd Length: 94 Bit Score: 42.41 E-value: 8.53e-05

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 24111244 452 TVREGSPAELQCEVRGKPRPPVLWSRvdKEAALLPSGLPLE---ETPDGK--LRLERVSRDMSGTYRC 514
Cdd:cd20951  11 TVWEKSDAKLRVEVQGKPDPEVKWYK--NGVPIDPSSIPGKykiESEYGVhvLHIRRVTVEDSAVYSA 76

First Ig-like domain of Junctional adhesion molecule-1 (JAM1)and similar domains; a member of the V-set of IgSF domains; The members here are composed of the first Ig-like domain of Junctional Adhesion Molecule-1 (JAM1)and similar domains. JAM1 is an immunoglobulin superfamily (IgSF) protein with two Ig-like domains in its extracellular region; it plays a role in the formation of endothelial and epithelial tight junction and acts as a receptor for mammalian reovirus sigma-1. The IgSF is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The first Ig-like domain of JAM1 is a member of the V-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C'-C" in the other.

Pssm-ID: 409538 Cd Length: 102 Bit Score: 42.14 E-value: 1.12e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 443 SVPKGRAVVTVREGSPAELQCEVRGKPRPP-VLWSRVDKE------------------AALLPSGlpleetpdgkLRLER 503
Cdd:cd20946   1 TVPSSQQVVTVVENQEVILSCKTPKKTSSPrVEWKKLQRDvtfvvfqnnkiqgdykgrAEILGTN----------ITIKN 70

                        90       100       110
                ....*....|....*....|....*....|....
gi 24111244 504 VSRDMSGTYRCQ-TARYNGFNVrpREAQVQLNVQ 536
Cdd:cd20946  71 VTRSDSGKYRCEvSARSDGQNL--GEVTVTLEVL 102

Immunoglobulin (Ig)-like domain of vascular endothelial growth factor (VEGF) receptor (R) and similar proteins; member of the I-set of IgSF domains; The members here are composed of the immunoglobulin (Ig)-like domain of vascular endothelial growth factor (VEGF) receptor (R) and related proteins. The VEGFRs have an extracellular component with seven Ig-like domains, a transmembrane segment, and an intracellular tyrosine kinase domain interrupted by a kinase-insert domain. The VEGFR family consists of three members: VEGFR-1 (Flt-1), VEGFR-2 (KDR/Flk-1) and VEGFR-3 (Flt-4). VEGF-A interacts with both VEGFR-1 and VEGFR-2. VEGFR-1 binds strongest to VEGF; VEGF-2 binds more weakly. VEGFR-3 appears not to bind VEGF, but binds other members of the VEGF family (VEGF-C and -D). VEGFRs bind VEGFs with high affinity with the IG-like domains. VEGF-A is important to the growth and maintenance of vascular endothelial cells and to the development of new blood- and lymphatic-vessels in physiological and pathological states. VEGFR-2 is a major mediator of the mitogenic, angiogenic, and microvascular permeability-enhancing effects of VEGF-A. VEGFR-1 may play an inhibitory part in these processes by binding VEGF and interfering with its interaction with VEGFR-2. VEGFR-1 has a signaling role in mediating monocyte chemotaxis. VEGFR-1 and VEGFR-2 may mediate a chemotactic and a survival signal in hematopoietic stem cells or leukemia cells. VEGFR-3 has been shown to be involved in tumor angiogenesis and growth. This group also contains alpha-type platelet-derived growth factor receptor precursor (PDGFR)-alpha (CD140a), and PDGFR-beta (CD140b). PDGFRs alpha and beta have an extracellular component with five Ig-like domains, a transmembrane segment, and a cytoplasmic portion that has protein tyrosine kinase activity.

Pssm-ID: 409404 Cd Length: 102 Bit Score: 42.14 E-value: 1.27e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 242 LKLSVNETLVVNP-GENVTVQCLLTGGDPL-PQLQWS-----HGPGPLPLGALAQGG--------TLSIPSVQARDSGYY 306
Cdd:cd05742   3 LELSPNAEPTVLPqGETLVLNCTANVNLNEvVDFQWTypsekEGKLALLKPDIKVDWsepgefvsTLTIPEATLKDSGTY 82

                        90       100
                ....*....|....*....|.
gi 24111244 307 NCTATNnvgNPAKKTVNLLVR 327
Cdd:cd05742  83 TCAARS---GVMKKEKQTSVS 100

Fourth immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues, and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409388 Cd Length: 84 Bit Score: 41.41 E-value: 1.30e-04

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 24111244  52 EGDTLMLQCLVTGHPRPQVRWTKTAGSA--SDKFQetSVFNETLRIERIARTQGGRYYCKAENGVG 115
Cdd:cd05723  11 ESMDIVFECEVTGKPTPTVKWVKNGDVVipSDYFK--IVKEHNLQVLGLVKSDEGFYQCIAENDVG 74

Immunoglobulin (Ig)-like domain of myotilin, palladin, and myopalladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain in myotilin, palladin, and myopalladin. Myotilin, palladin, and myopalladin function as scaffolds that regulate actin organization. Myotilin and myopalladin are most abundant in skeletal and cardiac muscle; palladin is ubiquitously expressed in the organs of developing vertebrates and plays a key role in cellular morphogenesis. The three family members each interact with specific molecular partners with all three binding to alpha-actinin; In addition, palladin also binds to vasodilator-stimulated phosphoprotein (VASP) and ezrin, myotilin binds to filamin and actin, and myopalladin also binds to nebulin and cardiac ankyrin repeat protein (CARP). This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409405 [Multi-domain] Cd Length: 91 Bit Score: 41.71 E-value: 1.38e-04

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 24111244 250 LVVNPGENVTVQCLLTGgDPLPQLQWSHGPGPLPLGA-----LAQGG--TLSIPSVQARDSGYYNCTATNNVG 315
Cdd:cd05744  10 LEVQEGRLCRFDCKVSG-LPTPDLFWQLNGKPVRPDSahkmlVRENGrhSLIIEPVTKRDAGIYTCIARNRAG 81

Second immunoglobulin (Ig)-like domain of a Follistatin-related protein 5, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in human Follistatin-related protein 5 (FSTL5) and a follistatin-like molecule encoded by the CNS-related Mahya gene. Mahya genes have been retained in certain Bilaterian branches during evolution. They are conserved in Hymenoptera and Deuterostomes, but are absent from other metazoan species such as fruit fly and nematode. Mahya proteins are secretory, with a follistatin-like domain (Kazal-type serine/threonine protease inhibitor domain and EF-hand calcium-binding domain), two Ig-like domains, and a novel C-terminal domain. Mahya may be involved in learning and memory and in processing of sensory information in Hymenoptera and vertebrates. Follistatin is a secreted, multidomain protein that binds activins with high affinity and antagonizes their signaling.

Pssm-ID: 409399 [Multi-domain] Cd Length: 93 Bit Score: 41.86 E-value: 1.40e-04

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 24111244 248 ETLVVNPGENVTVQCLLTGgDPLPQLQW-SHGPGPLP-----LGALAQGGTLSIPSVQARDSGYYNCTATNNVG 315
Cdd:cd05736   8 EFQAKEPGVEASLRCHAEG-IPLPRVQWlKNGMDINPklskqLTLIANGSELHISNVRYEDTGAYTCIAKNEGG 80

Immunoglobulin (Ig)-like domain of human titin C terminus and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain from the C-terminus of human titin x and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is gigantic; depending on isoform composition it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone and appears to function similar to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 143224 [Multi-domain] Cd Length: 92 Bit Score: 41.19 E-value: 1.85e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 332 ATFQITPDVIKESEniqlGQDLKLSCHVDAVPQEKVTyqWFKNGKPARMSKRLLVTRNDpelpaVTSSLELIDLHFSDYG 411
Cdd:cd05747   4 ATILTKPRSLTVSE----GESARFSCDVDGEPAPTVT--WMREGQIIVSSQRHQITSTE-----YKSTFEISKVQMSDEG 72


                ..
gi 24111244 412 TY 413
Cdd:cd05747  73 NY 74

Fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related); The members here are composed of the fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related). These proteins belong to the L1 subfamily of cell adhesion molecules (CAMs) and are comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. These molecules are primarily expressed in the nervous system. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth.

Pssm-ID: 409367 [Multi-domain] Cd Length: 89 Bit Score: 40.89 E-value: 2.07e-04

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 24111244 452 TVREGSPAELQCEVRGKPRPPVLWSRvdkeaallpSGLPLEETPD--------GKLRLERVSRDMSGTYRC 514
Cdd:cd04978  10 VLSPGETGELICEAEGNPQPTITWRL---------NGVPIEPAPEdmrrtvdgRTLIFSNLQPNDTAVYQC 71

Immunoglobulin (Ig)-like domain of myotilin, palladin, and myopalladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain in myotilin, palladin, and myopalladin. Myotilin, palladin, and myopalladin function as scaffolds that regulate actin organization. Myotilin and myopalladin are most abundant in skeletal and cardiac muscle; palladin is ubiquitously expressed in the organs of developing vertebrates and plays a key role in cellular morphogenesis. The three family members each interact with specific molecular partners with all three binding to alpha-actinin; In addition, palladin also binds to vasodilator-stimulated phosphoprotein (VASP) and ezrin, myotilin binds to filamin and actin, and myopalladin also binds to nebulin and cardiac ankyrin repeat protein (CARP). This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409405 [Multi-domain] Cd Length: 91 Bit Score: 40.94 E-value: 2.10e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244  49 TIREGDTLMLQCLVTGHPRPQVRWTKTAGSASDKFQETSVFNE----TLRIERIARTQGGRYYCKAENGVGVPAIkSIRV 124
Cdd:cd05744  11 EVQEGRLCRFDCKVSGLPTPDLFWQLNGKPVRPDSAHKMLVREngrhSLIIEPVTKRDAGIYTCIARNRAGENSF-NAEL 89


                ..
gi 24111244 125 DV 126
Cdd:cd05744  90 VV 91

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

Pssm-ID: 464026 [Multi-domain] Cd Length: 79 Bit Score: 40.46 E-value: 2.26e-04

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 24111244    49 TIREGDTLMLQCLVTGHPRPQVRWTKtAGSASDKFQETSVFNetlrierIARTQGGRYYCKAENGVGVPAIKSIRVDV 126
Cdd:pfam13895  10 VVTEGEPVTLTCSAPGNPPPSYTWYK-DGSAISSSPNFFTLS-------VSAEDSGTYTCVARNGRGGKVSNPVELTV 79

Third immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the third immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143222 [Multi-domain] Cd Length: 74 Bit Score: 40.31 E-value: 2.36e-04

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 24111244 455 EGSPAELQCEVRGKPRPPVLWSR------VDKEAALLPSglpleetpdGKLRLERVSRDMSGTYRCQ 515
Cdd:cd05745   1 EGQTVDFLCEAQGYPQPVIAWTKggsqlsVDRRHLVLSS---------GTLRISRVALHDQGQYECQ 58

Immunoglobulin (Ig)-like domain of titin and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain found in titin-like proteins and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is a giant protein; depending on isoform composition, it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone. It appears to function similarly to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. Within the sarcomere, titin is also attached to or is associated with myosin binding protein C (MyBP-C). MyBP-C appears to contribute to the generation of passive tension by titin and like titin has repeated Ig-like and FN-III domains. Also included in this group are worm twitchin and insect projectin, thick filament proteins of invertebrate muscle which also have repeated Ig-like and FN-III domains.

Pssm-ID: 409406 [Multi-domain] Cd Length: 82 Bit Score: 40.27 E-value: 3.09e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 249 TLVVNPGENVTVQCLLTGgDPLPQLQWSHGPGPLPLGALAQ------GGTLSIPSVQARDSGYYNCTATNNVGnPAKKTV 322
Cdd:cd05748   1 TIVVRAGESLRLDIPIKG-RPTPTVTWSKDGQPLKETGRVQiettasSTSLVIKNAKRSDSGKYTLTLKNSAG-EKSATI 78


                ....
gi 24111244 323 NLLV 326
Cdd:cd05748  79 NVKV 82

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409549 [Multi-domain] Cd Length: 88 Bit Score: 40.59 E-value: 3.20e-04

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 248 ETLVVNPGENVTVQCLLTGgDPLPQLQWSHGPGPLPLGALAQGG---TLSIPSVQARDSGYYNCTATNNV 314
Cdd:cd20957   9 PVQTVDFGRTAVFNCSVTG-NPIHTVLWMKDGKPLGHSSRVQILsedVLVIPSVKREDKGMYQCFVRNDG 77

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409570 [Multi-domain] Cd Length: 88 Bit Score: 40.45 E-value: 3.23e-04

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 24111244  52 EGDTLMLQCLVTGHPRPQVRWTKTAGSASDKFQETSVFNETLRIERIARTQGGRYYCKAENGVG 115
Cdd:cd20978  15 GGQDVTLPCQVTGVPQPKITWLHNGKPLQGPMERATVEDGTLTIINVQPEDTGYYGCVATNEIG 78

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 1 (NCAM-1); The members here are composed of the fourth Ig domain of Neural Cell Adhesion Molecule 1(NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM) and heterophilic (NCAM-non-NCAM) interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions), through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain. One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 143277 [Multi-domain] Cd Length: 97 Bit Score: 40.73 E-value: 3.66e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 238 APPALKLSVNETlVVNPGENVTVQCLLTGgDPLPQLQWSHG-----------PGPLPLGALAQGGTLSIPSVQARDSGYY 306
Cdd:cd05869   1 AKPKITYVENQT-AMELEEQITLTCEASG-DPIPSITWRTStrnisseektlDGHIVVRSHARVSSLTLKYIQYTDAGEY 78


                ....*....
gi 24111244 307 NCTATNNVG 315
Cdd:cd05869  79 LCTASNTIG 87

First immunoglobulin (Ig)-like domain of Tyro3 receptor tyrosine kinase (RTK), and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain of Tyro3 receptor tyrosine kinase (RTK). Tyro3 together with Axl and Mer form the Axl/Tyro3 family of receptor tyrosine kinases (RTKs). This family includes Axl (also known as Ark, Ufo, and Tyro7), Tyro3 (also known as Sky, Rse, Brt, Dtk, and Tif), and Mer (also known as Nyk, c-Eyk, and Tyro12). Axl/Tyro3 family receptors have an extracellular portion with two Ig-like domains followed by two fibronectin-types III (FNIII) domains, a membrane-spanning single helix, and a cytoplasmic tyrosine kinase domain. Axl, Tyro3 and Mer are widely expressed in adult tissues, though they show higher expression in the brain, in the lymphatic and vascular systems, and in the testis. Axl, Tyro3, and Mer bind the vitamin K dependent protein Gas6 with high affinity, and in doing so activate their tyrosine kinase activity. Axl/Gas6 signaling may play a part in cell adhesion processes, prevention of apoptosis, and cell proliferation.

Pssm-ID: 409553 Cd Length: 87 Bit Score: 40.12 E-value: 3.94e-04

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244  49 TIREGDTLMLQCLVTGHPRPQVRWTKTAGSASDKFQETSVFNET-----LRIERIARTQGGRYYCKAENG 113
Cdd:cd20961   4 TVSQGQPVKLNCSVEGMEEPDIQWVKDGAVVQNLDQLYIPVSEQhwigfLSLKSVERSDAGRYWCQVEDG 73

agrin-responsive second immunoglobulin-like domains (Ig2) of the Muscle-specific kinase (MuSK) ectodomain; a member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin-like (Ig) domains of the Muscle-specific kinase (MuSK) ectodomain. MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409560 [Multi-domain] Cd Length: 88 Bit Score: 40.30 E-value: 3.94e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 237 TAPPalklsVNETLVVnpGENVTVQCLlTGGDPLPQLQWSHGPGPLPLG---ALAQGGTLSIPSVQARDSGYYNCTATNN 313
Cdd:cd20968   3 TRPP-----TNVTIIE--GLKAVLPCT-TMGNPKPSVSWIKGDDLIKENnriAVLESGSLRIHNVQKEDAGQYRCVAKNS 74

                        90
                ....*....|...
gi 24111244 314 VGNPAKKTVNLLV 326
Cdd:cd20968  75 LGIAYSKPVTIEV 87

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409549 [Multi-domain] Cd Length: 88 Bit Score: 40.21 E-value: 3.97e-04

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 24111244  43 ISERVYTIREGDTLMLQCLVTGHPRPQVRWTKT--AGSASDKFQETSVfnETLRIERIARTQGGRYYCKAEN 112
Cdd:cd20957   6 IDPPVQTVDFGRTAVFNCSVTGNPIHTVLWMKDgkPLGHSSRVQILSE--DVLVIPSVKREDKGMYQCFVRN 75

C-terminal immunoglobulin (Ig)-like domain of M-protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of M-protein (also known as myomesin-2). M-protein is a structural protein localized to the M-band, a transverse structure in the center of the sarcomere, and is a candidate for M-band bridges. M-protein is modular consisting mainly of repetitive IG-like and fibronectin type III (FnIII) domains and has a muscle-type specific expression pattern. M-protein is present in fast fibers.

Pssm-ID: 143299 Cd Length: 92 Bit Score: 40.28 E-value: 4.20e-04

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 24111244 450 VVTVREGSPAELQCEVRGKPRPPVLWSRVDKEAALLPSGL-PLEETPDGKLRLERVSRDMSGTY 512
Cdd:cd05891  10 VVTIMEGKTLNLTCTVFGNPDPEVIWFKNDQDIELSEHYSvKLEQGKYASLTIKGVTSEDSGKY 73

Fourth Ig-like domain from smooth muscle myosin light chain kinase and similar domains ; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain from smooth muscle myosin light chain kinase (MYLK) and similar domains. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of this group shows that the fourth Ig-like domain from myosin light chain kinase lacks this strand and thus belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409568 [Multi-domain] Cd Length: 90 Bit Score: 40.31 E-value: 4.53e-04

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 24111244  52 EGDTLMLQCLVTGHPRPQVRWTKTAGS---ASDKFQETSVFNEtLRIERIARTQGGRYYCKAENGVGVpAIKSIRVDV 126
Cdd:cd20976  15 EGQDFVAQCSARGKPVPRITWIRNAQPlqyAADRSTCEAGVGE-LHIQDVLPEDHGTYTCLAKNAAGQ-VSCSAWVTV 90

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 39.62 E-value: 4.59e-04

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 556 VLLRCSLlRGSPQriASAVWRFKGQLLPPPPVVPAAAEAPDhAELRLDAVTRDSSGSYECSVSNDVGSAA 625
Cdd:cd00096   1 VTLTCSA-SGNPP--PTITWYKNGKPLPPSSRDSRRSELGN-GTLTISNVTLEDSGTYTCVASNSAGGSA 66

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

Pssm-ID: 409544 [Multi-domain] Cd Length: 87 Bit Score: 39.79 E-value: 4.98e-04

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 24111244  48 YTIREGDTLMLQCLVTGHPRPQVRWTKTAGSASDKFQE-TSVFNETLRIERIARTQGGRYYCKAENGVG 115
Cdd:cd20952   9 QTVAVGGTVVLNCQATGEPVPTISWLKDGVPLLGKDERiTTLENGSLQIKGAEKSDTGEYTCVALNLSG 77

C-terminal immunoglobulin (Ig)-like domain of myomesin and M-protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of myomesin and M-protein (also known as myomesin-2). Myomesin and M-protein are both structural proteins localized to the M-band, a transverse structure in the center of the sarcomere, and are candidates for M-band bridges. Both proteins are modular, consisting mainly of repetitive Ig-like and fibronectin type III (FnIII) domains. Myomesin is expressed in all types of vertebrate striated muscle; M-protein has a muscle-type specific expression pattern. Myomesin is present in both slow and fast fibers; M-protein is present only in fast fibers. It has been suggested that myomesin acts as a molecular spring with alternative splicing as a means of modifying its elasticity.

Pssm-ID: 319300 Cd Length: 92 Bit Score: 39.88 E-value: 5.96e-04

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 24111244  47 VYTIREGDTLMLQCLVTGHPRPQVRWTKT--AGSASDKFQ-ETSVFNE-TLRIERIARTQGGRYYCKAENGVG 115
Cdd:cd05737  10 VVTIMEGKTLNLTCNVWGDPPPEVSWLKNdqALAFLDHCNlKVEAGRTvYFTINGVSSEDSGKYGLVVKNKYG 82

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409389 [Multi-domain] Cd Length: 87 Bit Score: 39.69 E-value: 6.10e-04

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 24111244 255 GENVTVQCLLTGGDPLPQLQWSHGPGPLPLGA----LAQGGTLSIPSVQARDSGYYNCTATNNVG----NPAKKTV 322
Cdd:cd05724  12 GEMAVLECSPPRGHPEPTVSWRKDGQPLNLDNervrIVDDGNLLIAEARKSDEGTYKCVATNMVGeresRAARLSV 87

C-terminal immunoglobulin (Ig)-like domain of myomesin and M-protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of myomesin and M-protein (also known as myomesin-2). Myomesin and M-protein are both structural proteins localized to the M-band, a transverse structure in the center of the sarcomere, and are candidates for M-band bridges. Both proteins are modular, consisting mainly of repetitive Ig-like and fibronectin type III (FnIII) domains. Myomesin is expressed in all types of vertebrate striated muscle; M-protein has a muscle-type specific expression pattern. Myomesin is present in both slow and fast fibers; M-protein is present only in fast fibers. It has been suggested that myomesin acts as a molecular spring with alternative splicing as a means of modifying its elasticity.

Pssm-ID: 319300 Cd Length: 92 Bit Score: 39.88 E-value: 6.20e-04

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 24111244 450 VVTVREGSPAELQCEVRGKPRPPVLWSRVDKEAALLPS-GLPLEETPDGKLRLERVSRDMSGTY 512
Cdd:cd05737  10 VVTIMEGKTLNLTCNVWGDPPPEVSWLKNDQALAFLDHcNLKVEAGRTVYFTINGVSSEDSGKY 73

Fifth immunoglobulin (Ig) domain of contactin; The members here are composed of the fifth immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409358 [Multi-domain] Cd Length: 89 Bit Score: 39.75 E-value: 6.77e-04

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*
gi 24111244 461 LQCEVRGKPRPPVLWSRVDKeaaLLPSGLPLEETPDGKLRLERVSRDMSGTYRCQ 515
Cdd:cd04969  22 IECKPKASPKPTISWSKGTE---LLTNSSRICILPDGSLKIKNVTKSDEGKYTCF 73

C-terminal immunoglobulin (Ig)-like domain of M-protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of M-protein (also known as myomesin-2). M-protein is a structural protein localized to the M-band, a transverse structure in the center of the sarcomere, and is a candidate for M-band bridges. M-protein is modular consisting mainly of repetitive IG-like and fibronectin type III (FnIII) domains and has a muscle-type specific expression pattern. M-protein is present in fast fibers.

Pssm-ID: 143299 Cd Length: 92 Bit Score: 39.51 E-value: 7.77e-04

                        10        20
                ....*....|....*....|....*...
gi 24111244  47 VYTIREGDTLMLQCLVTGHPRPQVRWTK 74
Cdd:cd05891  10 VVTIMEGKTLNLTCTVFGNPDPEVIWFK 37

C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin, and similar domains; member of the I-set IgSF domains; The members here are composed of the C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin and similar proteins, including Caenorhabditis elegans and Aplysia californica Twitchin, Drosophila melanogaster Projectin, and similar proteins. These are very large muscle proteins containing multiple immunoglobulin (Ig)-like and fibronectin type III (FN3) domains and a single kinase domain near the C-terminus. In humans these proteins are called Titin. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig-like domain of the Twitchin is a member of the I-set IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins (titin, telokin, and twitchin), the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D.

Pssm-ID: 409541 [Multi-domain] Cd Length: 89 Bit Score: 39.24 E-value: 8.14e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244  47 VYTIREGDTLMLQCLVTGHPRPQVRWTKTAGSASDKFQETSVFN---ETLRIERIARTQGGRYYCKAENgvgvpaIKSIR 123
Cdd:cd20949   8 VTTVKEGQSATILCEVKGEPQPNVTWHFNGQPISASVADMSKYRilaDGLLINKVTQDDTGEYTCRAYQ------VNSIA 81


                ....*.
gi 24111244 124 VDVQYL 129
Cdd:cd20949  82 SDMQER 87

First immunoglobulin (Ig) domain of contactin; member of the I-set of (Ig) superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409356 [Multi-domain] Cd Length: 96 Bit Score: 39.53 E-value: 8.29e-04

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 24111244 256 ENVTVQCLLTGgDPLPQLQWSHGPGPLPLGALAQ----GGTLSIPS-VQARDSGYYNCTATNNVG 315
Cdd:cd04967  20 KKVALNCRARA-NPVPSYRWLMNGTEIDLESDYRyslvDGTLVISNpSKAKDAGHYQCLATNTVG 83

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 1 (NCAM-1) and similar proteins; The members here are composed of the fourth immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule (NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-non-NCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions), through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain. Also included in this group is NCAM-2 (also known as OCAM/mamFas II and RNCAM) NCAM-2 is differentially expressed in the developing and mature olfactory epithelium (OE). One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 409395 [Multi-domain] Cd Length: 96 Bit Score: 39.43 E-value: 8.74e-04

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 247 NETLVVNpgENVTVQCLLTGgDPLPQLQWSHGP-----------GPLPLGALAQGGTLSIPSVQARDSGYYNCTATNNVG 315
Cdd:cd05732  10 NQTAVEL--EQITLTCEAEG-DPIPEITWRRATrgisfeegdldGRIVVRGHARVSSLTLKDVQLTDAGRYDCEASNRIG 86

agrin-responsive second immunoglobulin-like domains (Ig2) of the Muscle-specific kinase (MuSK) ectodomain; a member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin-like (Ig) domains of the Muscle-specific kinase (MuSK) ectodomain. MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409560 [Multi-domain] Cd Length: 88 Bit Score: 39.15 E-value: 9.05e-04

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 24111244 451 VTVREGSPAELQCEVRGKPRPPVLWSrvdKEAALLPSGLPLEETPDGKLRLERVSRDMSGTYRC 514
Cdd:cd20968   9 VTIIEGLKAVLPCTTMGNPKPSVSWI---KGDDLIKENNRIAVLESGSLRIHNVQKEDAGQYRC 69

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 39.10 E-value: 9.28e-04

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 24111244   349 LGQDLKLSCHVDAVPqEKVTYQWFKNGKparmSKRLLVTRNDPELPAVTSSLELIDLHFSDYGTYLCMASFPGAPVP 425
Cdd:pfam00047  10 EGDSATLTCSASTGS-PGPDVTWSKEGG----TLIESLKVKHDNGRTTQSSLLISNVTKEDAGTYTCVVNNPGGSAT 81

CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold domain; CD19, also known as B-Lymphocyte Surface Antigen B4, T-Cell Surface Antigen Leu-12, and CVID3, is a transmembrane receptor present on various types of B cells, including progenitor, naive, and memory B cells, as well as plasmablasts. Until recently, it was believed to comprise two extracellular immunoglobulin (Ig) structural domains arranged in tandem with C2 topology. However, recent crystal structures have shown that the CD19 extracellular domain contains a unique double Ig domain that is responsible for its binding to proteins such as CD21, CD81, and CD225, which regulate B cell activation and survival. A recent analysis of the CD19 extracellular domain sequence reveals two "Ig domains", but the structure demonstrates that these two domains are not folded independently and connected in tandem. Rather, they fold together as one intertwined domain that can be referred to as a "double Ig" domain. Each of the two regular Ig domain sequences has a noticeably short linker that forms a loop between strands C' and D, rather than allowing the formation of a C" strand. Additionally, the two Ig-domain sequences are separated by a long linker that is structured as a small insertion domain, enabling both Ig sequences to fold together as a unique double Ig-domain. The CD19 domain comprises four "protodomains": two formed by A'B-CC' strands and two by DE-FG strands that interdigitate to form a novel double Ig fold. When analyzing this double Ig domain in terms of the usual Ig-fold, A'B-CC' protodomain of the first Ig sequence combines with DE-FG protodomain of the second, and vice versa. Hence, the second combined Ig fold is inverted, with DE-FG protodomain of the first Ig sequence combining with A'B-CC' protodomain of the second Ig sequence and in that order, as if it were a circular permutation, obtained only through structural folding.

Pssm-ID: 467824 Cd Length: 89 Bit Score: 39.24 E-value: 9.60e-04

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 24111244 250 LVVNPGENVTVQCLLTGGDPLP-QLQWSHGPGPLPLGALAQGGT------------LSIPSVQARDSGYYNC 308
Cdd:cd23997   3 VTVAEGSTLWLPCLVPPSDGPRgPLTWSRGHPKTPLLSLELGSPglwvlvgplgilLLLPNVSAQMGGFYLC 74

Immunoglobulin variable domain (IgV); The members here are composed of the immunoglobulin variable domain (IgV). The IgV family contains the standard Ig superfamily V-set AGFCC'C"/DEB domain topology, and are components of immunoglobulin (Ig) and T cell receptors. The basic structure of Ig molecules is a tetramer of two light chains and two heavy chains linked by disulfide bonds. In Ig, each chain is composed of one variable domain (IgV) and one or more constant domains (IgC); these names reflect the fact that the variability in sequences is higher in the variable domain than in the constant domain. Within the variable domain, there are regions of even more variability called the hypervariable or complementarity-determining regions (CDRs) which are responsible for antigen binding. A predominant feature of most Ig domains is the disulfide bridge connecting 2 beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E and, D strands in one sheet and A', G, F, C, C', and C" strands in the other.

Pssm-ID: 409355 [Multi-domain] Cd Length: 111 Bit Score: 39.62 E-value: 1.01e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 249 TLVVNPGENVTVQCLLTGGDPLPQLQW-------------SHGPGPLPLGALAQGG-----------TLSIPSVQARDSG 304
Cdd:cd00099   7 SLSVQEGESVTLSCEVSSSFSSTYIYWyrqkpgqgpefliYLSSSKGKTKGGVPGRfsgsrdgtssfSLTISNLQPEDSG 86

                        90
                ....*....|..
gi 24111244 305 YYNCTATNNVGN 316
Cdd:cd00099  87 TYYCAVSESGGT 98

Immunoglobulin domain of human Synaptic Adhesion-Like Molecule 5 (SALM5) and similar proteins; member of the I-set of IgSF domains; This group contains the immunoglobulin domain of human Synaptic Adhesion-Like Molecule 5 (SALM5) and similar proteins. The SALM (for synaptic adhesion-like molecules; also known as Lrfn for leucine-rich repeat and fibronectin type III domain containing) family of adhesion molecules consists of five known members: SALM1/Lrfn2, SALM2/Lrfn1, SALM3/Lrfn4, SALM4/Lrfn3, and SALM5/Lrfn5. SALMs share a similar domain structure, containing leucine-rich repeats (LRRs), an immunoglobulin (Ig) domain, and a fibronectin III (FNIII) domain, followed by a transmembrane domain and a C-terminal PDZ-binding motif. SALM5 is implicated in autism spectrum disorders (ASDs) and schizophrenia, induces presynaptic differentiation in contacting axons. SALM5 interacts with the Ig domains of LAR (Leukocyte common Antigen-Related) family receptor protein tyrosine phosphatases (LAR-RPTPs; LAR, PTPdelta, and PTPsigma). In addition, PTPdelta is implicated in ASDs, ADHD, bipolar disorder, and restless leg syndrome. Studies have shown that LAR-RPTPs are novel and splicing-dependent presynaptic ligands for SALM5, and that they mediate SALM5-dependent presynaptic differentiation. Furthermore, SALM5 maintains AMPA receptor (AMPAR)-mediated excitatory synaptic transmission through mechanisms involving the interaction of SALM5 with LAR-RPTPs. This group belongs to the I-set of immunoglobulin superfamily (IgSF) domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409421 [Multi-domain] Cd Length: 88 Bit Score: 39.00 E-value: 1.11e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 250 LVVNPGENVTVQCLLTGgDPLPQLQWSHGPGPL----PLGALAQGGTLSIPSVQARDSGYYNCTATNNVGNpAKKTVNLL 325
Cdd:cd05764  10 LRVLEGQRATLRCKARG-DPEPAIHWISPEGKLisnsSRTLVYDNGTLDILITTVKDTGAFTCIASNPAGE-ATARVELH 87


                .
gi 24111244 326 V 326
Cdd:cd05764  88 I 88

Third immunoglobulin (Ig) domain of contactin-1; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 143259 Cd Length: 88 Bit Score: 38.85 E-value: 1.18e-03

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244  53 GDTLMLQCLVTGHPRPQVRWTKTAgSASDKFQETSVFNETLRIERIARTQGGRYYCKAEN 112
Cdd:cd05851  16 GQNVTLECFALGNPVPVIRWRKIL-EPMPATAEISMSGAVLKIFNIQPEDEGTYECEAEN 74

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409389 [Multi-domain] Cd Length: 87 Bit Score: 38.54 E-value: 1.30e-03

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 24111244 451 VTVREGSPAELQCEV-RGKPRPPVLWSRVDKEAALlpSGLPLEETPDGKLRLERVSRDMSGTYRC 514
Cdd:cd05724   7 TQVAVGEMAVLECSPpRGHPEPTVSWRKDGQPLNL--DNERVRIVDDGNLLIAEARKSDEGTYKC 69

Fifth immunoglobulin (Ig) domain of contactin; The members here are composed of the fifth immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409358 [Multi-domain] Cd Length: 89 Bit Score: 38.60 E-value: 1.34e-03

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 24111244 267 GDPLPQLQWSHGPGPLPLGA---LAQGGTLSIPSVQARDSGYYNCTATNNVGNpAKKTVNLLV 326
Cdd:cd04969  28 ASPKPTISWSKGTELLTNSSricILPDGSLKIKNVTKSDEGKYTCFAVNFFGK-ANSTGSLSV 89

First Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409566 [Multi-domain] Cd Length: 93 Bit Score: 38.87 E-value: 1.35e-03

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 24111244 451 VTVREGSPAELQCEVRGKPRPPVLWSRvDKEAALLpSGLPLEE--TPDG--KLRLERVSRDMSGTY 512
Cdd:cd20974  10 VVVLEGSTATFEAHVSGKPVPEVSWFR-DGQVIST-STLPGVQisFSDGraKLSIPAVTKANSGRY 73

Second Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409564 [Multi-domain] Cd Length: 91 Bit Score: 38.72 E-value: 1.48e-03

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 24111244 452 TVREGSPAELQCEVRGKPRPPVLWSRVDKEaallpsglpLEETPDGK---------LRLERVSRDMSGTYRC 514
Cdd:cd20972  12 EVAEGSKVRLECRVTGNPTPVVRWFCEGKE---------LQNSPDIQihqegdlhsLIIAEAFEEDTGRYSC 74

Third immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the third immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The third Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules, including vascular (VCAM), intercellular (ICAM), neural (NCAM) and mucosal addressin (MADCAM) cell adhesion molecules, as well as junction adhesion molecules (JAM).

Pssm-ID: 409569 Cd Length: 93 Bit Score: 38.53 E-value: 1.75e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244  49 TIREGDTLMLQCLVTGHPRPQVRWTKTaGSASDKFQETsvfnetlRIERIARTQGGR-------------YYCKAENGVG 115
Cdd:cd20977  11 MAKAGDVTMIYCMYGSNPTAHPNYFKN-GKDVNGNPED-------RITRHNRTSGKRllfkttlpedegvYTCEVDNGVG 82

                        90
                ....*....|.
gi 24111244 116 VPAIKSIRVDV 126
Cdd:cd20977  83 KPQKHSLKLTV 93

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 38.33 E-value: 1.82e-03

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 24111244   451 VTVREGSPAELQCEVR-GKPRPPVLWSRVDKEaalLPSGLPLEETPDGK----LRLERVSRDMSGTYRCQT 516
Cdd:pfam00047   6 VTVLEGDSATLTCSAStGSPGPDVTWSKEGGT---LIESLKVKHDNGRTtqssLLISNVTKEDAGTYTCVV 73

Immunoglobulin-like domain of human Aortic Preferentially Expressed Protein-1 (APEG-1) and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin I-set (IgI) domain of the Human Aortic Preferentially Expressed Protein-1 (APEG-1) and similar proteins. APEG-1 is a novel specific smooth muscle differentiation marker predicted to play a role in the growth and differentiation of arterial smooth muscle cells (SMCs). The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the human APEG-1 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409567 Cd Length: 91 Bit Score: 38.22 E-value: 2.10e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 452 TVREGSPAELQCEVRGKPRPPVLWSRvDKEAALLPSGLPLEETPDG--KLRLERVSRDMSGTYRCQTAryNGFNVRPREA 529
Cdd:cd20975  11 SVREGQDVIMSIRVQGEPKPVVSWLR-NRQPVRPDQRRFAEEAEGGlcRLRILAAERGDAGFYTCKAV--NEYGARQCEA 87


                ....
gi 24111244 530 QVQL 533
Cdd:cd20975  88 RLEV 91

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor, and similar domains; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three Ig-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans. This group also contains fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409393 [Multi-domain] Cd Length: 95 Bit Score: 38.35 E-value: 2.27e-03

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 24111244  45 ERVYTIREGDTLMLQCLVTGHPRPQVRWTKtagSASDKFQE-----TSVFNE--TLRIERIARTQGGRYYCKAENGVG 115
Cdd:cd05729  11 EREHALPAANKVRLECGAGGNPMPNITWLK---DGKEFKKEhriggTKVEEKgwSLIIERAIPRDKGKYTCIVENEYG 85

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 37.87 E-value: 2.33e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244    543 PSSQDVRqaLGRPVLLRCSLLRGSPQRIasaVWRFKGQLLPPPPVVPAAAEAPDHAELRLDAVTRDSSGSYECSVSNDVG 622
Cdd:smart00410   1 PPSVTVK--EGESVTLSCEASGSPPPEV---TWYKQGGKLLAESGRFSVSRSGSTSTLTISNVTPEDSGTYTCAATNSSG 75


                   ....*....
gi 24111244    623 SAACLFQVS 631
Cdd:smart00410  76 SASSGTTLT 84

C-terminal immunoglobulin (Ig)-like domain of myotilin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of myotilin. Mytolin belongs to the palladin-myotilin-myopalladin family. Proteins belonging to the latter family contain multiple Ig-like domains and function as scaffolds, modulating the actin cytoskeleton. Myotilin is most abundant in skeletal and cardiac muscle and is involved in maintaining sarcomere integrity. It binds to alpha-actinin, filamin, and actin. Mutations in myotilin lead to muscle disorders. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409473 Cd Length: 92 Bit Score: 38.21 E-value: 2.44e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244  52 EGDTLMLQCLVTGHPRPQVRWTKTAGSASDKFQETSVFNE-----TLRIERIARTQGGRYYCKAENGVGVpAIKSIRVDV 126
Cdd:cd05892  14 EGDPVRLECQISAIPPPQIFWKKNNEMLQYNTDRISLYQDncgriCLLIQNANKKDAGWYTVSAVNEAGV-VSCNARLDV 92

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

Pssm-ID: 464026 [Multi-domain] Cd Length: 79 Bit Score: 37.76 E-value: 2.62e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244   350 GQDLKLSCHVDAVPqeKVTYQWFKNGKPARMSKRLLVtrndpelPAVTSslelidlhfSDYGTYLCMASFPGAPVPDLSV 429
Cdd:pfam13895  14 GEPVTLTCSAPGNP--PPSYTWYKDGSAISSSPNFFT-------LSVSA---------EDSGTYTCVARNGRGGKVSNPV 75


                  ....
gi 24111244   430 EVNI 433
Cdd:pfam13895  76 ELTV 79

Third immunoglobulin domain in Cluster of Differentiation (CD) 22; member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain in Cluster of Differentiation (CD) 22 (also known as Siglec-2). CD22, a sialic-acid binding immunoglobulin type-lectin (Siglec) family member, is an inhibitory co-receptor of the B-cell receptor (BCR). The inhibitory function of CD22 and its restricted expression on B cells makes CD22 an attractive target against dysregulated B cells that cause autoimmune diseases and B-cell-derived cancers. CD22 plays a vital role in establishing a baseline level of B-cell inhibition, and thus is an important determinant of homeostasis in humoral immunity. Siglecs are primarily expressed on immune cells and recognize sialic acid-containing glycan ligands. Siglecs are organized as an extracellular module composed of Ig-like domains (an N-terminal variable set of Ig-like carbohydrate recognition domains, and 1 to 16 constant Ig-like domains), followed by transmembrane and short cytoplasmic domains. Human Siglecs are classified into two subgroups, one subgroup is comprised of sialoadhesin (Siglec-1), CD22 (Siglec-2), and MAG (Siglec-4, myelin-associated glycoprotein), the other subgroup is comprised of CD33-related Siglecs which include CD33 (Siglec-3) and human Siglecs 5-11. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409531 Cd Length: 88 Bit Score: 37.86 E-value: 3.05e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244  50 IREGDTLMLQCLVTG-HPR-PQVRWTKTAGSAsdKFQETSvfneTLRIERIARTQGGRYYCKAENGVGVPAIKSIRVDVQ 127
Cdd:cd20937  14 VREGDSVTMTCEVSSsNPEyTTVSWLKDGTSL--KKQNTF----TLNLREVTKDQSGKYCCQVSNDVGPGRSEEVFLQVQ 87


                .
gi 24111244 128 Y 128
Cdd:cd20937  88 Y 88

immunoglobulin-like domain of telokin and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin (Ig) domain in telokin, the C-terminal domain of myosin light chain kinase which is identical to telokin, and similar proteins. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the telokin Ig domain lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409565 [Multi-domain] Cd Length: 88 Bit Score: 37.55 E-value: 3.38e-03

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 24111244  49 TIREGDTLMLQCLVTGHPRPQVRWTKTAGSASDKFQETSVFNE----TLRIERIARTQGGRYYCKAENGVG 115
Cdd:cd20973   8 EVVEGSAARFDCKVEGYPDPEVKWMKDDNPIVESRRFQIDQDEdglcSLIISDVCGDDSGKYTCKAVNSLG 78

Immunoglobulin I-set domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1); The members here are composed of the immunoglobulin I-set (IgI) domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1). Human Lingo-1 is a central nervous system-specific transmembrane glycoprotein also known as LERN-1, which functions as a negative regulator of neuronal survival, axonal regeneration, and oligodendrocyte differentiation and myelination. Lingo-1 is a key component of the Nogo receptor signaling complex (RTN4R/NGFR) in RhoA activation responsible for some inhibition of axonal regeneration by myelin-associated factors. The ligand-binding ectodomain of human Lingo-1 contains a bimodular, kinked structure composed of leucine-rich repeat (LRR) and immunoglobulin (Ig)-like modules. Diseases associated with Lingo-1 include mental retardation, autosomal recessive 64 and essential tremor. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the Lingo-1 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409561 Cd Length: 92 Bit Score: 37.75 E-value: 3.59e-03

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 24111244  47 VYTIREGDTLMLQCLVTGHPRPQVRWT---KTAGSASDKFQETSVFNETLRIERIARTQGGRYYCKAENGVG 115
Cdd:cd20969  11 QVFVDEGHTVQFVCRADGDPPPAILWLsprKHLVSAKSNGRLTVFPDGTLEVRYAQVQDNGTYLCIAANAGG 82

Second immunoglobulin (Ig)-like domain found in Leukocyte Ig-like receptors, Natural killer inhibitory receptors (KIRs) and similar domains; member of Immunoglobulin Constant-2 set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in Leukocyte Ig-like receptors (LILRs), Natural killer inhibitory receptors (KIRs, also known as also known as cluster of differentiation (CD) 158), and similar proteins. This group includes LILRB1 (also known as LIR-1), LILRA5 (also known as LIR9), an activating natural cytotoxicity receptor NKp46, the immune-type receptor glycoprotein VI (GPVI), and the IgA-specific receptor Fc-alphaRI (also known as cluster of differentiation (CD) 89). LILRs are a family of immunoreceptors expressed on expressed on T and B cells, on monocytes, dendritic cells, and subgroups of natural killer (NK) cells. The human LILR family contains nine proteins (LILRA1-3, and 5, and LILRB1-5). From functional assays, and as the cytoplasmic domains of various LILRs, for example LILRB1, LILRB2 (also known as LIR-2), and LILRB3 (also known as LIR-3) contain immunoreceptor tyrosine-based inhibitory motifs (ITIMs), it is thought that LIR proteins are inhibitory receptors. Of the eight LIR family proteins, only LILRB1, and LILRB2, show detectable binding to class I MHC molecules; ligands for the other members have yet to be determined. The extracellular portions of the different LIR proteins contain different numbers of Ig-like domains for example, four in the case of LILRB1, and LILRB2, and two in the case of LILRB4 (also known as LIR-5). The activating natural cytotoxicity receptor NKp46 is expressed in natural killer cells, and is organized as an extracellular portion having two Ig-like extracellular domains, a transmembrane domain, and a small cytoplasmic portion. GPVI, which also contains two Ig-like domains, participates in the processes of collagen-mediated platelet activation and arterial thrombus formation. Fc-alphaRI is expressed on monocytes, eosinophils, neutrophils, and macrophages; it mediates IgA-induced immune effector responses such as phagocytosis, antibody-dependent cell-mediated cytotoxicity and respiratory burst. Killer cell immunoglobulin-like receptors (KIRs; also known as CD158 for human KIR) are transmembrane glycoproteins expressed by natural killer cells and subsets of T cells. KIRs are a family of highly polymorphic activating and inhibitory receptors that serve as key regulators of human NK cell function. The KIR proteins are classified by the number of extracellular immunoglobulin domains (2D or 3D) and by whether they have a long (L) or short (S) cytoplasmic domain. KIR proteins with the long cytoplasmic domain transduce inhibitory signals upon ligand binding via an immune tyrosine-based inhibitory motif (ITIM), while KIR proteins with the short cytoplasmic domain lack the ITIM motif and instead associate with the TYRO protein tyrosine kinase binding protein to transduce activating signals. The major ligands for KIR are MHC class I (HLA-A, -B or -C) molecules.

Pssm-ID: 409376 Cd Length: 90 Bit Score: 37.38 E-value: 3.78e-03

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                ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 24111244 244 LSVNETLVVNPGENVTVQC---------LLT--GGDPLPQLQWSHGPGPLPLGA--LAQGGTL 293
Cdd:cd05711   4 LSAHPGPVVPSGENVTLQChsrigfdrfILYkeGRSPLLQFHGSGFQASFPLGPvtPAHAGTY 66

Sixth immunoglobulin (Ig) domain of contactin; The members here are composed of the sixth immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409359 Cd Length: 102 Bit Score: 37.91 E-value: 4.06e-03

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                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 252 VNPGENVTVQCLLTGgDPLPQLQ--WSHGPGPLPL----------GALAQGGTLSIPSVQARDSGYYNCTATNNVGNpAK 319
Cdd:cd04970  14 ITVGENATLQCHASH-DPTLDLTftWSFNGVPIDLekieghyrrrYGKDSNGDLEIVNAQLKHAGRYTCTAQTVVDS-DS 91


                ....*...
gi 24111244 320 KTVNLLVR 327
Cdd:cd04970  92 ASATLVVR 99

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

Pssm-ID: 409544 [Multi-domain] Cd Length: 87 Bit Score: 37.09 E-value: 4.50e-03

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 24111244 447 GRAVVTVREGSPAELQCEVRGKPRPPVLWSRvdkEAALLPSGLP-LEETPDGKLRLERVSRDMSGTYRC 514
Cdd:cd20952   5 GPQNQTVAVGGTVVLNCQATGEPVPTISWLK---DGVPLLGKDErITTLENGSLQIKGAEKSDTGEYTC 70

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 37.17 E-value: 4.76e-03

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244    48 YTIREGDTLMLQCLV-TGHPRPQVRWTKTAG----SASDKFQETSVFNETLRIERIARTQGGRYYCKAENGVGVPAIKSI 122
Cdd:pfam00047   6 VTVLEGDSATLTCSAsTGSPGPDVTWSKEGGtlieSLKVKHDNGRTTQSSLLISNVTKEDAGTYTCVVNNPGGSATLSTS 85

First immunoglobulin (Ig)-like constant domain in Robo (roundabout) receptors, and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain in Roundabout (Robo) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit1, Slit2, Slit3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit1, Slit2,and Slit3 are expressed at the ventral midline. Robo3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site.

Pssm-ID: 409490 [Multi-domain] Cd Length: 99 Bit Score: 37.53 E-value: 5.30e-03

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 24111244 451 VTVREGSPAELQCEVRGKPRPPVLWsrvdkeaalLPSGLPLEET-----------PDGKLRLERV-----SRDMSGTYRC 514
Cdd:cd07693  10 LIVSKGDPATLNCKAEGRPTPTIQW---------LKNGQPLETDkddprshrivlPSGSLFFLRVvhgrkGRSDEGVYVC 80

                        90
                ....*....|....*....
gi 24111244 515 QTARYNGfNVRPREAQVQL 533
Cdd:cd07693  81 VAHNSLG-EAVSRNASLEV 98

Third immunoglobulin domain of Nectin-like Protein-5, and similar domains; The members here are composed of the third immunoglobulin domain of Nectin-like Protein-5 (also known as Cluster of Differentiation 155 (CD155)). Nectin-like Protein-5 mediates NK (Natural Killer) cell adhesion and triggers NK cell effector functions. CD155 binds two different NK cell receptors: CD96 and CD226. These interactions accumulate at the cell-cell contact site, leading to the formation of a mature immunological synapse between NK cell and target cell. This may trigger adhesion and secretion of lytic granules and IFN-gamma and activate cytotoxicity of activated NK cells. CD155 may also promote NK cell-target cell modular exchange, and PVR transfer to the NK cell. This transfer is more important in some tumor cells expressing a lot of PVR, and may trigger fratricide NK cell activation, providing tumors with a mechanism of immunoevasion. Moreover, CD155 plays a role in mediating tumor cell invasion and migration.

Pssm-ID: 409524 Cd Length: 86 Bit Score: 36.77 E-value: 5.47e-03

                        10        20        30        40
                ....*....|....*....|....*....|....*....|..
gi 24111244 275 WSHGPGPLPLGALAQGGTLSIPSVQARDSGYYNCTATNNVGN 316
Cdd:cd20930  36 WSTTSGPFPTSAVAQGPQLLIHSVDRLVNTTFICTVTNAVGT 77

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor_like-1(FGFRL1); member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 is comprised of a signal peptide, three extracellular Ig-like modules, a transmembrane segment, and a short intracellular domain. FGFRL1 is expressed preferentially in skeletal tissues. Similar to FGF receptors, the expressed protein interacts specifically with heparin and with FGF2. FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409442 Cd Length: 92 Bit Score: 36.76 E-value: 6.83e-03

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 24111244  53 GDTLMLQCLVTGHPRPQVRWTKTAGS-ASDKFQETSVFNETLRIERIARTQGGRYYCKAENGVG 115
Cdd:cd05856  19 GSSVRLKCVASGNPRPDITWLKDNKPlTPPEIGENKKKKWTLSLKNLKPEDSGKYTCHVSNRAG 82

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409570 [Multi-domain] Cd Length: 88 Bit Score: 36.60 E-value: 7.39e-03

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 24111244 450 VVTVREGSPAELQCEVRGKPRPPVLWSRvdkeaallpSGLPLEETP------DGKLRLERVSRDMSGTYRCQTARYNG 521
Cdd:cd20978  10 NVVVKGGQDVTLPCQVTGVPQPKITWLH---------NGKPLQGPMeratveDGTLTIINVQPEDTGYYGCVATNEIG 78

Fourth immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM); The members here are composed of the fourth immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region, and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM.

Pssm-ID: 409453 [Multi-domain] Cd Length: 89 Bit Score: 36.41 E-value: 8.52e-03

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*....
gi 24111244 456 GSPAELQCEVRGKPRPPVLWSRvdkeaallpSGLPLEET-PDGKLRLER 503
Cdd:cd05867  14 GETARLDCQVEGIPTPNITWSI---------NGAPIEGTdPDPRRHVSS 53