Abstract
The basic function of the Src homology 3 (SH3) domain is considered to be binding to proline-rich sequences containing a PxxP motif. Recently, many SH3 domains, including those from Grb2 and Pex13p, were reported to bind sequences lacking a PxxP motif. We report here that the 22 residue peptide lacking a PxxP motif, derived from p47(phox), binds to the C-terminal SH3 domain from p67(phox). We applied the NMR cross-saturation method to locate the interaction sites for the non-PxxP peptides on their cognate SH3 domains from p67(phox), Grb2 and Pex13p. The binding site of the Grb2 SH3 partially overlapped the conventional PxxP-binding site, whereas those of p67(phox) and Pex13p SH3s are located in different surface regions. The non-PxxP peptide from p47(phox) binds to the p67(phox) SH3 more tightly when it extends to the N-terminus to include a typical PxxP motif, which enabled the structure determination of the complex, to reveal that the non-PxxP peptide segment interacted with the p67(phox) SH3 in a compact helix-turn-helix structure (PDB entry 1K4U).
MeSH terms
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Adaptor Proteins, Signal Transducing*
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Amino Acid Motifs
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Amino Acid Sequence
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Binding Sites
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CSK Tyrosine-Protein Kinase
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Escherichia coli
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GRB2 Adaptor Protein
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Humans
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Ligands
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Membrane Proteins / metabolism*
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Models, Molecular
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Molecular Sequence Data
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Mutation
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NADPH Oxidases
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Peptides, Cyclic / metabolism
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Phosphoproteins / metabolism*
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Protein Binding
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Protein Conformation
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Protein-Tyrosine Kinases / metabolism
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Proteins / metabolism*
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
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Saccharomyces cerevisiae Proteins / metabolism
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Sequence Deletion
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src Homology Domains / physiology*
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src-Family Kinases
Substances
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Adaptor Proteins, Signal Transducing
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GRB2 Adaptor Protein
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GRB2 protein, human
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Ligands
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Membrane Proteins
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PEX13 protein, S cerevisiae
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PEX13 protein, human
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Peptides, Cyclic
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Phosphoproteins
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Proteins
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Recombinant Fusion Proteins
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Saccharomyces cerevisiae Proteins
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cyclo-acetyl-(cysteinyl-histidyl-phenylalanyl-glutaminyl-phenylalanyl-cysteinyl)amide
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neutrophil cytosol factor 67K
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NADPH Oxidases
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neutrophil cytosolic factor 1
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Protein-Tyrosine Kinases
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CSK Tyrosine-Protein Kinase
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src-Family Kinases
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CSK protein, human