Medium chain reductase/dehydrogenase (MDR)/zinc-dependent alcohol dehydrogenase-like family; The medium chain reductase/dehydrogenases (MDR)/zinc-dependent alcohol dehydrogenase-like family, which contains the zinc-dependent alcohol dehydrogenase (ADH-Zn) and related proteins, is a diverse group of proteins related to the first identified member, class I mammalian ADH. MDRs display a broad range of activities and are distinguished from the smaller short chain dehydrogenases (~ 250 amino acids vs. the ~ 350 amino acids of the MDR). The MDR proteins have 2 domains: a C-terminal NAD(P) binding-Rossmann fold domain of a beta-alpha form and an N-terminal catalytic domain with distant homology to GroES. The MDR group contains a host of activities, including the founding alcohol dehydrogenase (ADH) , quinone reductase, sorbitol dehydrogenase, formaldehyde dehydrogenase, butanediol DH, ketose reductase, cinnamyl reductase, and numerous others. The zinc-dependent alcohol dehydrogenases (ADHs) catalyze the NAD(P)(H)-dependent interconversion of alcohols to aldehydes or ketones. ADH-like proteins typically form dimers (typically higher plants, mammals) or tetramers (yeast, bacteria), and generally have 2 tightly bound zinc atoms per subunit, a catalytic zinc at the active site and a structural zinc in a lobe of the catalytic domain. The active site zinc is coordinated by a histidine, two cysteines, and a water molecule. The second zinc seems to play a structural role, affects subunit interactions, and is typically coordinated by 4 cysteines. Other MDR members have only a catalytic zinc, and some contain no coordinated zinc.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|..
gi 20513825   1 QCRECNACLNPEGNLCIRSDLTG-RGVLADGTTRFTCKGKPVQHFMNTSTFT 51
Cdd:cd08299  95 QCGKCRACLNPESNLCLKNDLGKpQGLMQDGTSRFTCKGKPIHHFLGTSTFS 146

class I, II, IV alcohol dehydrogenases; NAD(P)(H)-dependent oxidoreductases are the major enzymes in the interconversion of alcohols and aldehydes or ketones. This group includes alcohol dehydrogenases corresponding to mammalian classes I, II, IV. Alcohol dehydrogenase in the liver converts ethanol and NAD+ to acetaldehyde and NADH, while in yeast and some other microorganisms ADH catalyzes the conversion acetaldehyde to ethanol in alcoholic fermentation. ADH is a member of the medium chain alcohol dehydrogenase family (MDR), which have a NAD(P)(H)-binding domain in a Rossmann fold of a beta-alpha form. The NAD(H)-binding region is comprised of 2 structurally similar halves, each of which contacts a mononucleotide. A GxGxxG motif after the first mononucleotide contact half allows the close contact of the coenzyme with the ADH backbone. The N-terminal catalytic domain has a distant homology to GroES. These proteins typically form dimers (typically higher plants, mammals) or tetramers (yeast, bacteria), and have 2 tightly bound zinc atoms per subunit, a catalytic zinc at the active site and a structural zinc in a lobe of the catalytic domain. NAD(H) binding occurs in the cleft between the catalytic and coenzyme-binding domains at the active site, and coenzyme binding induces a conformational closing of this cleft. Coenzyme binding typically precedes and contributes to substrate binding. In human ADH catalysis, the zinc ion helps coordinate the alcohol, followed by deprotonation of a histidine (His-51), the ribose of NAD, a serine (Ser-48) , then the alcohol, which allows the transfer of a hydride to NAD+, creating NADH and a zinc-bound aldehyde or ketone. In yeast and some bacteria, the active site zinc binds an aldehyde, polarizing it, and leading to the reverse reaction.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|..
gi 20513825   1 QCRECNACLNPEGNLCIRSDLTG-RGVLADGTTRFTCKGKPVQHFMNTSTFT 51
Cdd:cd08299  95 QCGKCRACLNPESNLCLKNDLGKpQGLMQDGTSRFTCKGKPIHHFLGTSTFS 146

Alcohol dehydrogenase-like

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 20513825    1 QCRECNACLNPEGNLC--IRSDLTGRGVLADGTTRFTCK--GKPVQHFMNTSTFT 51
Cdd:PLN02740 100 ECGDCRYCKRDKTNLCetYRVDPFKSVMVNDGKTRFSTKgdGQPIYHFLNTSTFT 154

class I, II, IV alcohol dehydrogenases; NAD(P)(H)-dependent oxidoreductases are the major enzymes in the interconversion of alcohols and aldehydes or ketones. This group includes alcohol dehydrogenases corresponding to mammalian classes I, II, IV. Alcohol dehydrogenase in the liver converts ethanol and NAD+ to acetaldehyde and NADH, while in yeast and some other microorganisms ADH catalyzes the conversion acetaldehyde to ethanol in alcoholic fermentation. ADH is a member of the medium chain alcohol dehydrogenase family (MDR), which have a NAD(P)(H)-binding domain in a Rossmann fold of a beta-alpha form. The NAD(H)-binding region is comprised of 2 structurally similar halves, each of which contacts a mononucleotide. A GxGxxG motif after the first mononucleotide contact half allows the close contact of the coenzyme with the ADH backbone. The N-terminal catalytic domain has a distant homology to GroES. These proteins typically form dimers (typically higher plants, mammals) or tetramers (yeast, bacteria), and have 2 tightly bound zinc atoms per subunit, a catalytic zinc at the active site and a structural zinc in a lobe of the catalytic domain. NAD(H) binding occurs in the cleft between the catalytic and coenzyme-binding domains at the active site, and coenzyme binding induces a conformational closing of this cleft. Coenzyme binding typically precedes and contributes to substrate binding. In human ADH catalysis, the zinc ion helps coordinate the alcohol, followed by deprotonation of a histidine (His-51), the ribose of NAD, a serine (Ser-48) , then the alcohol, which allows the transfer of a hydride to NAD+, creating NADH and a zinc-bound aldehyde or ketone. In yeast and some bacteria, the active site zinc binds an aldehyde, polarizing it, and leading to the reverse reaction.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|..
gi 20513825   1 QCRECNACLNPEGNLCIRSDLTG-RGVLADGTTRFTCKGKPVQHFMNTSTFT 51
Cdd:cd08299  95 QCGKCRACLNPESNLCLKNDLGKpQGLMQDGTSRFTCKGKPIHHFLGTSTFS 146

Liver alcohol dehydrogenase; NAD(P)(H)-dependent oxidoreductases are the major enzymes in the interconversion of alcohols and aldehydes, or ketones. Alcohol dehydrogenase in the liver converts ethanol and NAD+ to acetaldehyde and NADH, while in yeast and some other microorganisms ADH catalyzes the conversion acetaldehyde to ethanol in alcoholic fermentation. There are 7 vertebrate ADH 7 classes, 6 of which have been identified in humans. Class III, glutathione-dependent formaldehyde dehydrogenase, has been identified as the primordial form and exists in diverse species, including plants, micro-organisms, vertebrates, and invertebrates. Class I, typified by liver dehydrogenase, is an evolving form. Gene duplication and functional specialization of ADH into ADH classes and subclasses created numerous forms in vertebrates. For example, the A, B and C (formerly alpha, beta, gamma) human class I subunits have high overall structural similarity, but differ in the substrate binding pocket and therefore in substrate specificity. In human ADH catalysis, the zinc ion helps coordinate the alcohol, followed by deprotonation of a histidine (His-51), the ribose of NAD, a serine (Ser-48) , then the alcohol, which allows the transfer of a hydride to NAD+, creating NADH and a zinc-bound aldehyde or ketone. In yeast and some bacteria, the active site zinc binds an aldehyde, polarizing it, and leading to the reverse reaction. ADH is a member of the medium chain alcohol dehydrogenase family (MDR), which has a NAD(P)(H)-binding domain in a Rossmann fold of an beta-alpha form. The NAD(H)-binding region is comprised of 2 structurally similar halves, each of which contacts a mononucleotide. A GxGxxG motif after the first mononucleotide contact half allows the close contact of the coenzyme with the ADH backbone. The N-terminal catalytic domain has a distant homology to GroES. These proteins typically form dimers (typically higher plants, mammals) or tetramers (yeast, bacteria), and have 2 tightly bound zinc atoms per subunit, a catalytic zinc at the active site and a structural zinc in a lobe of the catalytic domain. NAD(H) binding occurs in the cleft between the catalytic and coenzyme-binding domains at the active site, and coenzyme binding induces a conformational closing of this cleft. Coenzyme binding typically precedes and contributes to substrate binding.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|.
gi 20513825   1 QCRECNACLNPEGNLCIRSDLTGRGVLADGTTRFTCKGKPVQHFMNTSTFT 51
Cdd:cd08277  90 QCGECSNCRSGKTNLCQKYRANESGLMPDGTSRFTCKGKKIYHFLGTSTFS 140

Plant alcohol dehydrogenase; NAD(P)(H)-dependent oxidoreductases are the major enzymes in the interconversion of alcohols and aldehydes or ketones. Alcohol dehydrogenase in the liver converts ethanol and NAD+ to acetaldehyde and NADH, while in yeast and some other microorganisms ADH catalyzes the conversion acetaldehyde to ethanol in alcoholic fermentation. There are 7 vertebrate ADH 7 classes, 6 of which have been identified in humans. Class III, glutathione-dependent formaldehyde dehydrogenase, has been identified as the primordial form and exists in diverse species, including plants, micro-organisms, vertebrates, and invertebrates. Class I, typified by liver dehydrogenase, is an evolving form. Gene duplication and functional specialization of ADH into ADH classes and subclasses created numerous forms in vertebrates. For example, the A, B and C (formerly alpha, beta, gamma) human class I subunits have high overall structural similarity, but differ in the substrate binding pocket and therefore in substrate specificity. In human ADH catalysis, the zinc ion helps coordinate the alcohol, followed by deprotonation of a histidine (His-51), the ribose of NAD, a serine (Ser-48) , then the alcohol, which allows the transfer of a hydride to NAD+, creating NADH and a zinc-bound aldehyde or ketone. In yeast and some bacteria, the active site zinc binds an aldehyde, polarizing it, and leading to the reverse reaction. ADH is a member of the medium chain alcohol dehydrogenase family (MDR), which has a NAD(P)(H)-binding domain in a Rossmann fold of an beta-alpha form. The NAD(H)-binding region is comprised of 2 structurally similar halves, each of which contacts a mononucleotide. A GxGxxG motif after the first mononucleotide contact half allows the close contact of the coenzyme with the ADH backbone. The N-terminal catalytic domain has a distant homology to GroES. These proteins typically form dimers (typically higher plants, mammals) or tetramers (yeast, bacteria), and have 2 tightly bound zinc atoms per subunit, a catalytic zinc at the active site and a structural zinc in a lobe of the catalytic domain. NAD(H) binding occurs in the cleft between the catalytic and coenzyme-binding domains at the active site, and coenzyme binding induces a conformational closing of this cleft. Coenzyme binding typically precedes and contributes to substrate binding.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|...
gi 20513825   1 QCRECNACLNPEGNLC--IRSDLTGRGVLADGTTRFTCKGKPVQHFMNTSTFT 51
Cdd:cd08301  91 ECKECRHCKSEKSNMCdlLRINTDRGVMINDGKSRFSINGKPIYHFVGTSTFS 143

Class III alcohol dehydrogenase; Glutathione-dependent formaldehyde dehydrogenases (FDHs, Class III ADH) are members of the zinc-dependent/medium chain alcohol dehydrogenase family. FDH converts formaldehyde and NAD(P) to formate and NAD(P)H. The initial step in this process the spontaneous formation of a S-(hydroxymethyl)glutathione adduct from formaldehyde and glutathione, followed by FDH-mediated oxidation (and detoxification) of the adduct to S-formylglutathione. NAD(P)(H)-dependent oxidoreductases are the major enzymes in the interconversion of alcohols and aldehydes or ketones. Alcohol dehydrogenase in the liver converts ethanol and NAD+ to acetaldehyde and NADH, while in yeast and some other microorganisms ADH catalyzes the conversion acetaldehyde to ethanol in alcoholic fermentation. Class III ADH are also known as glutathione-dependent formaldehyde dehydrogenase (FDH), which convert aldehydes to corresponding carboxylic acid and alcohol. ADH is a member of the medium chain alcohol dehydrogenase family (MDR), which has a NAD(P)(H)-binding domain in a Rossmann fold of an beta-alpha form. The NAD(H)-binding region is comprised of 2 structurally similar halves, each of which contacts a mononucleotide. A GxGxxG motif after the first mononucleotide contact half allows the close contact of the coenzyme with the ADH backbone. The N-terminal catalytic domain has a distant homology to GroES. These proteins typically form dimers (typically higher plants, mammals) or tetramers (yeast, bacteria), and have 2 tightly bound zinc atoms per subunit, a catalytic zinc at the active site and a structural zinc in a lobe of the catalytic domain. NAD(H) binding occurs in the cleft between the catalytic and coenzyme-binding domains at the active site, and coenzyme binding induces a conformational closing of this cleft. Coenzyme binding typically precedes and contributes to substrate binding.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*....
gi 20513825   2 CRECNACLNPEGNLCIRSDLTGRGVLADGTTRFTCKGKPVQHFMNTSTF 50
Cdd:cd08279  89 CGTCRYCSRGQPNLCDLGAGILGGQLPDGTRRFTADGEPVGAMCGLGTF 137

Alcohol dehydrogenase-like

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|..
gi 20513825    1 QCRECNACLNPEGNLCIRSDLTGRGVL-ADGTTRFTCKGKPVQHFMNTSTFT 51
Cdd:PLN02827  98 ECGSCRHCISGKSNMCQVLGLERKGVMhSDQKTRFSIKGKPVYHYCAVSSFS 149