Rossmann-fold NAD(P)(+)-binding proteins; A large family of proteins that share a Rossmann-fold NAD(P)H/NAD(P)(+) binding (NADB) domain. The NADB domain is found in numerous dehydrogenases of metabolic pathways such as glycolysis, and many other redox enzymes. NAD binding involves numerous hydrogen-bonds and van der Waals contacts, in particular H-bonding of residues in a turn between the first strand and the subsequent helix of the Rossmann-fold topology. Characteristically, this turn exhibits a consensus binding pattern similar to GXGXXG, in which the first 2 glycines participate in NAD(P)-binding, and the third facilitates close packing of the helix to the beta-strand. Typically, proteins in this family contain a second domain in addition to the NADB domain, which is responsible for specifically binding a substrate and catalyzing a particular enzymatic reaction.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   6 KVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAGvqCKAALDEQFEPQKTLFIQCDVADQQQLRDTFRKVVDHFGRL 85
Cdd:cd05323     1 KVAIITGGASGIGLATAKLLLKKGAKVAILDRNENPG--AAAELQAINPKVKATFVQCDVTSWEQLAAAFKKAIEKFGRV 78

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1391723718  86 DILVNNAGVNNEK----------NWEKTLQINLVSVISGTYLGLDYMSKQNGGEGGIIINMSSLAG 141
Cdd:cd05323    79 DILINNAGILDEKsylfagklppPWEKTIDVNLTGVINTTYLALHYMDKNKGGKGGVIVNIGSVAG 144

insect type alcohol dehydrogenase (ADH)-like, classical (c) SDRs; This subgroup contains insect type ADH, and 15-hydroxyprostaglandin dehydrogenase (15-PGDH) type I; these proteins are classical SDRs. ADH catalyzes the NAD+-dependent oxidation of alcohols to aldehydes/ketones. This subgroup is distinct from the zinc-dependent alcohol dehydrogenases of the medium chain dehydrogenase/reductase family, and evolved in fruit flies to allow the digestion of fermenting fruit. 15-PGDH catalyzes the NAD-dependent interconversion of (5Z,13E)-(15S)-11alpha,15-dihydroxy-9-oxoprost-13-enoate and (5Z,13E)-11alpha-hydroxy-9,15-dioxoprost-13-enoate, and has a typical SDR glycine-rich NAD-binding motif, which is not fully present in ADH. SDRs are a functionally diverse family of oxidoreductases that have a single domain with a structurally conserved Rossmann fold (alpha/beta folding pattern with a central beta-sheet), an NAD(P)(H)-binding region, and a structurally diverse C-terminal region. Classical SDRs are typically about 250 residues long, while extended SDRs are approximately 350 residues. Sequence identity between different SDR enzymes are typically in the 15-30% range, but the enzymes share the Rossmann fold NAD-binding motif and characteristic NAD-binding and catalytic sequence patterns. These enzymes catalyze a wide range of activities including the metabolism of steroids, cofactors, carbohydrates, lipids, aromatic compounds, and amino acids, and act in redox sensing. Classical SDRs have an TGXXX[AG]XG cofactor binding motif and a YXXXK active site motif, with the Tyr residue of the active site motif serving as a critical catalytic residue (Tyr-151, human 15-hydroxyprostaglandin dehydrogenase (15-PGDH) numbering). In addition to the Tyr and Lys, there is often an upstream Ser (Ser-138, 15-PGDH numbering) and/or an Asn (Asn-107, 15-PGDH numbering) contributing to the active site; while substrate binding is in the C-terminal region, which determines specificity. The standard reaction mechanism is a 4-pro-S hydride transfer and proton relay involving the conserved Tyr and Lys, a water molecule stabilized by Asn, and nicotinamide. Extended SDRs have additional elements in the C-terminal region, and typically have a TGXXGXXG cofactor binding motif. Complex (multidomain) SDRs such as ketoreductase domains of fatty acid synthase have a GGXGXXG NAD(P)-binding motif and an altered active site motif (YXXXN). Fungal type ketoacyl reductases have a TGXXXGX(1-2)G NAD(P)-binding motif. Some atypical SDRs have lost catalytic activity and/or have an unusual NAD(P)-binding motif and missing or unusual active site residues. Reactions catalyzed within the SDR family include isomerization, decarboxylation, epimerization, C=N bond reduction, dehydratase activity, dehalogenation, Enoyl-CoA reduction, and carbonyl-alcohol oxidoreduction.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   6 KVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAGvqCKAALDEQFEPQKTLFIQCDVADQQQLRDTFRKVVDHFGRL 85
Cdd:cd05323     1 KVAIITGGASGIGLATAKLLLKKGAKVAILDRNENPG--AAAELQAINPKVKATFVQCDVTSWEQLAAAFKKAIEKFGRV 78

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1391723718  86 DILVNNAGVNNEK----------NWEKTLQINLVSVISGTYLGLDYMSKQNGGEGGIIINMSSLAG 141
Cdd:cd05323    79 DILINNAGILDEKsylfagklppPWEKTIDVNLTGVINTTYLALHYMDKNKGGKGGVIVNIGSVAG 144

NAD(P)-dependent dehydrogenase, short-chain alcohol dehydrogenase family [Lipid transport and metabolism]; NAD(P)-dependent dehydrogenase, short-chain alcohol dehydrogenase family is part of the Pathway/BioSystem: Fatty acid biosynthesis

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   5 GKVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAGVQCKAALDEqfEPQKTLFIQCDVADQQQLRDTFRKVVDHFGR 84
Cdd:COG1028     6 GKVALVTGGSSGIGRAIARALAAEGARVVITDRDAEALEAAAAELRA--AGGRALAVAADVTDEAAVEALVAAAVAAFGR 83

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1391723718  85 LDILVNNAGVNN--------EKNWEKTLQINLVSVISGTYLGLDYMSKQnggEGGIIINMSSLAGI 142
Cdd:COG1028    84 LDILVNNAGITPpgpleeltEEDWDRVLDVNLKGPFLLTRAALPHMRER---GGGRIVNISSIAGL 146

SDR family mycofactocin-dependent oxidoreductase; Members of this protein subfamily are putative oxidoreductases belonging to the larger SDR family. All members occur in genomes that encode a cassette for the biosynthesis of mycofactocin, a proposed electron carrier of a novel redox pool. Characterized members of this family are described as NDMA-dependent, meaning that a blue aniline dye serving as an artificial electron acceptor is required for members of this family to cycle in vitro, since the bound NAD residue is not exchangeable. This family resembles TIGR03971 most closely in the N-terminal region, consistent with the published hypothesis of NAD interaction with mycofactocin. See EC 1.1.99.36. [Unknown function, Enzymes of unknown specificity]

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   5 GKVALVTGAAQGIGRAFAEALLLKGAKVALVDWNL-EAGVQCKAALDEQFE------PQKTLFIQCDVADQQQLRDTFRK 77
Cdd:TIGR04504   1 GRVALVTGAARGIGAATVRRLAADGWRVVAVDLCAdDPAVGYPLATRAELDavaaacPDQVLPVIADVRDPAALAAAVAL 80

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|...
gi 1391723718  78 VVDHFGRLDILVNNAGV---------NNEKNWEKTLQINLVSV 111
Cdd:TIGR04504  81 AVERWGRLDAAVAAAGViaggrplweTTDAELDLLLDVNLRGV 123

This enzymatic domain is part of bacterial polyketide synthases; It catalyses the first step in the reductive modification of the beta-carbonyl centres in the growing polyketide chain. It uses NADPH to reduce the keto group to a hydroxy group.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718    6 KVALVTGAAQGIGRAFAEALLLKGA-KVALV------DWNLEAGVQCKAALDEQfepqkTLFIQCDVADQQQLRDTFRKV 78
Cdd:smart00822   1 GTYLITGGLGGLGRALARWLAERGArRLVLLsrsgpdAPGAAALLAELEAAGAR-----VTVVACDVADRDALAAVLAAI 75

                           90
                   ....*....|....*.
gi 1391723718   79 VDHFGRLDILVNNAGV 94
Cdd:smart00822  76 PAVEGPLTGVIHAAGV 91

insect type alcohol dehydrogenase (ADH)-like, classical (c) SDRs; This subgroup contains insect type ADH, and 15-hydroxyprostaglandin dehydrogenase (15-PGDH) type I; these proteins are classical SDRs. ADH catalyzes the NAD+-dependent oxidation of alcohols to aldehydes/ketones. This subgroup is distinct from the zinc-dependent alcohol dehydrogenases of the medium chain dehydrogenase/reductase family, and evolved in fruit flies to allow the digestion of fermenting fruit. 15-PGDH catalyzes the NAD-dependent interconversion of (5Z,13E)-(15S)-11alpha,15-dihydroxy-9-oxoprost-13-enoate and (5Z,13E)-11alpha-hydroxy-9,15-dioxoprost-13-enoate, and has a typical SDR glycine-rich NAD-binding motif, which is not fully present in ADH. SDRs are a functionally diverse family of oxidoreductases that have a single domain with a structurally conserved Rossmann fold (alpha/beta folding pattern with a central beta-sheet), an NAD(P)(H)-binding region, and a structurally diverse C-terminal region. Classical SDRs are typically about 250 residues long, while extended SDRs are approximately 350 residues. Sequence identity between different SDR enzymes are typically in the 15-30% range, but the enzymes share the Rossmann fold NAD-binding motif and characteristic NAD-binding and catalytic sequence patterns. These enzymes catalyze a wide range of activities including the metabolism of steroids, cofactors, carbohydrates, lipids, aromatic compounds, and amino acids, and act in redox sensing. Classical SDRs have an TGXXX[AG]XG cofactor binding motif and a YXXXK active site motif, with the Tyr residue of the active site motif serving as a critical catalytic residue (Tyr-151, human 15-hydroxyprostaglandin dehydrogenase (15-PGDH) numbering). In addition to the Tyr and Lys, there is often an upstream Ser (Ser-138, 15-PGDH numbering) and/or an Asn (Asn-107, 15-PGDH numbering) contributing to the active site; while substrate binding is in the C-terminal region, which determines specificity. The standard reaction mechanism is a 4-pro-S hydride transfer and proton relay involving the conserved Tyr and Lys, a water molecule stabilized by Asn, and nicotinamide. Extended SDRs have additional elements in the C-terminal region, and typically have a TGXXGXXG cofactor binding motif. Complex (multidomain) SDRs such as ketoreductase domains of fatty acid synthase have a GGXGXXG NAD(P)-binding motif and an altered active site motif (YXXXN). Fungal type ketoacyl reductases have a TGXXXGX(1-2)G NAD(P)-binding motif. Some atypical SDRs have lost catalytic activity and/or have an unusual NAD(P)-binding motif and missing or unusual active site residues. Reactions catalyzed within the SDR family include isomerization, decarboxylation, epimerization, C=N bond reduction, dehydratase activity, dehalogenation, Enoyl-CoA reduction, and carbonyl-alcohol oxidoreduction.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   6 KVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAGvqCKAALDEQFEPQKTLFIQCDVADQQQLRDTFRKVVDHFGRL 85
Cdd:cd05323     1 KVAIITGGASGIGLATAKLLLKKGAKVAILDRNENPG--AAAELQAINPKVKATFVQCDVTSWEQLAAAFKKAIEKFGRV 78

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1391723718  86 DILVNNAGVNNEK----------NWEKTLQINLVSVISGTYLGLDYMSKQNGGEGGIIINMSSLAG 141
Cdd:cd05323    79 DILINNAGILDEKsylfagklppPWEKTIDVNLTGVINTTYLALHYMDKNKGGKGGVIVNIGSVAG 144

NAD(P)-dependent dehydrogenase, short-chain alcohol dehydrogenase family [Lipid transport and metabolism]; NAD(P)-dependent dehydrogenase, short-chain alcohol dehydrogenase family is part of the Pathway/BioSystem: Fatty acid biosynthesis

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   5 GKVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAGVQCKAALDEqfEPQKTLFIQCDVADQQQLRDTFRKVVDHFGR 84
Cdd:COG1028     6 GKVALVTGGSSGIGRAIARALAAEGARVVITDRDAEALEAAAAELRA--AGGRALAVAADVTDEAAVEALVAAAVAAFGR 83

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1391723718  85 LDILVNNAGVNN--------EKNWEKTLQINLVSVISGTYLGLDYMSKQnggEGGIIINMSSLAGI 142
Cdd:COG1028    84 LDILVNNAGITPpgpleeltEEDWDRVLDVNLKGPFLLTRAALPHMRER---GGGRIVNISSIAGL 146

NADP-dependent 3-hydroxy acid dehydrogenase YdfG [Energy production and conversion]; NADP-dependent 3-hydroxy acid dehydrogenase YdfG is part of the Pathway/BioSystem: Pyrimidine degradation

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   1 MHVNGKVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAGVQCKAALDEQFepqktLFIQCDVADQQQLRDTFRKVVD 80
Cdd:COG4221     1 MSDKGKVALITGASSGIGAATARALAAAGARVVLAARRAERLEALAAELGGRA-----LAVPLDVTDEAAVEAAVAAAVA 75

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718  81 HFGRLDILVNNAGVN--------NEKNWEKTLQINLVSVISGTYLGLDYMSKQNggeGGIIINMSSLAGI 142
Cdd:COG4221    76 EFGRLDVLVNNAGVAllgpleelDPEDWDRMIDVNVKGVLYVTRAALPAMRARG---SGHIVNISSIAGL 142

Short-chain dehydrogenase [General function prediction only];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   1 MHVNGKVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAGVQCKAALDEqfEPQKTLFIQCDVADQQQLRDTFRKVVD 80
Cdd:COG0300     1 MSLTGKTVLITGASSGIGRALARALAARGARVVLVARDAERLEALAAELRA--AGARVEVVALDVTDPDAVAALAEAVLA 78

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1391723718  81 HFGRLDILVNNAGVN--------NEKNWEKTLQINLVSVISGTYLGLDYMSKQNggeGGIIINMSSLAGISSV 145
Cdd:COG0300    79 RFGPIDVLVNNAGVGgggpfeelDLEDLRRVFEVNVFGPVRLTRALLPLMRARG---RGRIVNVSSVAGLRGL 148

3-hydroxybutyrate dehydrogenase; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   3 VNGKVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAGVqcKAALDEQFEPQKTLFIQCDVADQQQLRDTFRKVVDHF 82
Cdd:PRK12429    2 LKGKVALVTGAASGIGLEIALALAKEGAKVVIADLNDEAAA--AAAEALQKAGGKAIGVAMDVTDEEAINAGIDYAVETF 79

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1391723718  83 GRLDILVNNAG---VNN------EKnWEKTLQINLVSVISGTYLGLDYMSKQNGGEggiIINMSSLAG 141
Cdd:PRK12429   80 GGVDILVNNAGiqhVAPiedfptEK-WKKMIAIMLDGAFLTTKAALPIMKAQGGGR---IINMASVHG 143

short chain dehydrogenase; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   4 NGKVALVTGAAQGIGRAFAEALLLKGAKVALVDWNlEAGVQCKAALDeqfePQKTLFIQCDVADQQQLRDTFRKVVDHFG 83
Cdd:PRK06841   14 SGKVAVVTGGASGIGHAIAELFAAKGARVALLDRS-EDVAEVAAQLL----GGNAKGLVCDVSDSQSVEAAVAAVISAFG 88

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 1391723718  84 RLDILVNNAGVN--------NEKNWEKTLQINLvsviSGTYLgldyMSKQNGGE-----GGIIINMSSLAGISSVCRHL 149
Cdd:PRK06841   89 RIDILVNSAGVAllapaedvSEEDWDKTIDINL----KGSFL----MAQAVGRHmiaagGGKIVNLASQAGVVALERHV 159

SDR family oxidoreductase;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   5 GKVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAGVQCKAALDEQFEPQKTLFIQCDVADQQQLRDTFRKVVDHFGR 84
Cdd:PRK07063    7 GKVALVTGAAQGIGAAIARAFAREGAAVALADLDAALAERAAAAIARDVAGARVLAVPADVTDAASVAAAVAAAEEAFGP 86

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1391723718  85 LDILVNNAGVN--------NEKNWEKTLQINLVSVISGTYLGLDYMSKQNGGEggiIINMSS 138
Cdd:PRK07063   87 LDVLVNNAGINvfadplamTDEDWRRCFAVDLDGAWNGCRAVLPGMVERGRGS---IVNIAS 145

3beta17beta hydroxysteroid dehydrogenase-like, classical (c) SDRs; This subgroup includes members identified as 3beta17beta hydroxysteroid dehydrogenase, 20beta hydroxysteroid dehydrogenase, and R-alcohol dehydrogenase. These proteins exhibit the canonical active site tetrad and glycine rich NAD(P)-binding motif of the classical SDRs. 17beta-dehydrogenases are a group of isozymes that catalyze activation and inactivation of estrogen and androgens, and include members of the SDR family. SDRs are a functionally diverse family of oxidoreductases that have a single domain with a structurally conserved Rossmann fold (alpha/beta folding pattern with a central beta-sheet), an NAD(P)(H)-binding region, and a structurally diverse C-terminal region. Classical SDRs are typically about 250 residues long, while extended SDRS are approximately 350 residues. Sequence identity between different SDR enzymes are typically in the 15-30% range, but the enzymes share the Rossmann fold NAD-binding motif and characteristic NAD-binding and catalytic sequence patterns. These enzymes have a 3-glycine N-terminal NAD(P)(H)-binding pattern (typically, TGxxxGxG in classical SDRs and TGxxGxxG in extended SDRs), while substrate binding is in the C-terminal region. A critical catalytic Tyr residue (Tyr-151, human 15-hydroxyprostaglandin dehydrogenase (15-PGDH) numbering), is often found in a conserved YXXXK pattern. In addition to the Tyr and Lys, there is often an upstream Ser (Ser-138, 15-PGDH numbering) and/or an Asn (Asn-107, 15-PGDH numbering) or additional Ser, contributing to the active site. Substrates for these enzymes include sugars, steroids, alcohols, and aromatic compounds. The standard reaction mechanism is a proton relay involving the conserved Tyr and Lys, as well as Asn (or Ser). Some SDR family members, including 17 beta-hydroxysteroid dehydrogenase contain an additional helix-turn-helix motif that is not generally found among SDRs.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   3 VNGKVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAGVQCKAALDEQfepqkTLFIQCDVADQQQLRDTFRKVVDHF 82
Cdd:cd05341     3 LKGKVAIVTGGARGLGLAHARLLVAEGAKVVLSDILDEEGQAAAAELGDA-----ARFFHLDVTDEDGWTAVVDTAREAF 77

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1391723718  83 GRLDILVNNAGVNNEKN--------WEKTLQINLVSVISGTYLGLDYMSKQNGGEggiIINMSSLAG 141
Cdd:cd05341    78 GRLDVLVNNAGILTGGTvetttleeWRRLLDINLTGVFLGTRAVIPPMKEAGGGS---IINMSSIEG 141

L-iditol 2-dehydrogenase;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   1 MHVNGKVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAGVQCKAALDEQfepqkTLFIQCDVADQQQLRDTFRKVVD 80
Cdd:PRK07067    2 MRLQGKVALLTGAASGIGEAVAERYLAEGARVVIADIKPARARLAALEIGPA-----AIAVSLDVTRQDSIDRIVAAAVE 76

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1391723718  81 HFGRLDILVNNAGV--------NNEKNWEKTLQINlvsvISGTYLGLDYMSKQ--NGGEGGIIINMSSLAG 141
Cdd:PRK07067   77 RFGGIDILFNNAALfdmapildISRDSYDRLFAVN----VKGLFFLMQAVARHmvEQGRGGKIINMASQAG 143

Enoyl-(Acyl carrier protein) reductase; This domain is found in Enoyl-(Acyl carrier protein) reductases.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718  12 GAA--QGIGRAFAEALLLKGAKVALVDWNLEAGVQCKAALDEQFEPqktlFIQCDVADQQQLRDTFRKVVDHFGRLDILV 89
Cdd:pfam13561   1 GAAneSGIGWAIARALAEEGAEVVLTDLNEALAKRVEELAEELGAA----VLPCDVTDEEQVEALVAAAVEKFGRLDILV 76

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1391723718  90 NNAGVNN----------EKNWEKTLQINLVSVISGTYLGLDYMskqngGEGGIIINMSSLAGISSV 145
Cdd:pfam13561  77 NNAGFAPklkgpfldtsREDFDRALDVNLYSLFLLAKAALPLM-----KEGGSIVNLSSIGAERVV 137

beta-Keto acyl carrier protein reductase (BKR), involved in Type II FAS, classical (c) SDRs; This subgroup includes the Escherichai coli K12 BKR, FabG. BKR catalyzes the NADPH-dependent reduction of ACP in the first reductive step of de novo fatty acid synthesis (FAS). FAS consists of four elongation steps, which are repeated to extend the fatty acid chain through the addition of two-carbo units from malonyl acyl-carrier protein (ACP): condensation, reduction, dehydration, and a final reduction. Type II FAS, typical of plants and many bacteria, maintains these activities on discrete polypeptides, while type I FAS utilizes one or two multifunctional polypeptides. BKR resembles enoyl reductase, which catalyzes the second reduction step in FAS. SDRs are a functionally diverse family of oxidoreductases that have a single domain with structurally conserved Rossmann fold (alpha/beta folding pattern with a central beta-sheet) NAD(P)(H) binding region and a structurally diverse C-terminal region. Classical SDRs are typically about 250 residues long, while extended SDRS are approximately 350 residues. Sequence identity between different SDR enzymes are typically in the 15-30% range, but the enzymes share the Rossmann fold NAD binding motif and characteristic NAD-binding and catalytic sequence patterns. These enzymes have a 3-glycine N-terminal NAD(P)(H) binding pattern: TGxxxGxG in classical SDRs. Extended SDRs have additional elements in the C-terminal region, and typically have a TGXXGXXG cofactor binding motif. Complex (multidomain) SDRs such as ketoreductase domains of fatty acid synthase have a GGXGXXG NAD(P) binding motif and an altered active site motif (YXXXN). Fungal type type ketoacyl reductases have a TGXXXGX(1-2)G NAD(P)-binding motif. Some atypical SDRs have lost catalytic activity and/or have an unusual NAD(P) binding motif and missing or unusual active site residues. Reactions catalyzed within the SDR family include isomerization, decarboxylation, epimerization, C=N bond reduction, dehydratase activity, dehalogenation, Enoyl-CoA reduction, and carbonyl-alcohol oxidoreduction. A critical catalytic Tyr residue (Tyr-151, human 15-hydroxyprostaglandin dehydrogenase (15-PGDH) numbering), is often found in a conserved YXXXK pattern. In addition to the Tyr and Lys, there is often an upstream Ser (Ser-138, 15-PGDH numbering) and/or an Asn (Asn-107, 15-PGDH numbering) or additional Ser, contributing to the active site. Substrates for these enzymes include sugars, steroids, alcohols, and aromatic compounds. The standard reaction mechanism is a proton relay involving the conserved Tyr-151 and Lys-155, and well as Asn-111 (or Ser). Some SDR family members, including 17 beta-hydroxysteroid dehydrogenase contain an additional helix-turn-helix motif that is not generally found among SDRs.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   6 KVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAgvqCKAALDEQFE-PQKTLFIQCDVADQQQLRDTFRKVVDHFGR 84
Cdd:cd05333     1 KVALVTGASRGIGRAIALRLAAEGAKVAVTDRSEEA---AAETVEEIKAlGGNAAALEADVSDREAVEALVEKVEAEFGP 77

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1391723718  85 LDILVNNAGVN--------NEKNWEKTLQINLVSVISGTYLGLDYMSKQNGGEggiIINMSSLAGI 142
Cdd:cd05333    78 VDILVNNAGITrdnllmrmSEEDWDAVINVNLTGVFNVTQAVIRAMIKRRSGR---IINISSVVGL 140

short chain dehydrogenase; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   4 NGKVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAGVQCKAALDEQfepqkTLFIQCDVADQQQLRDTFRKVVDHFG 83
Cdd:PRK08265    5 AGKVAIVTGGATLIGAAVARALVAAGARVAIVDIDADNGAAVAASLGER-----ARFIATDITDDAAIERAVATVVARFG 79

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1391723718  84 RLDILVNNA------GVNNEKN-WEKTLQINLVSVISGTYLGLDYMSKQnggeGGIIINMSSLAG 141
Cdd:PRK08265   80 RVDILVNLActylddGLASSRAdWLAALDVNLVSAAMLAQAAHPHLARG----GGAIVNFTSISA 140

meso-2,3-butanediol dehydrogenase-like, classical (c) SDRs; 2,3-butanediol dehydrogenases (BDHs) catalyze the NAD+ dependent conversion of 2,3-butanediol to acetonin; BDHs are classified into types according to their stereospecificity as to substrates and products. Included in this subgroup are Klebsiella pneumonia meso-BDH which catalyzes meso-2,3-butanediol to D(-)-acetonin, and Corynebacterium glutamicum L-BDH which catalyzes lX+)-2,3-butanediol to L(+)-acetonin. This subgroup is comprised of classical SDRs with the characteristic catalytic triad and NAD-binding motif. SDRs are a functionally diverse family of oxidoreductases that have a single domain with a structurally conserved Rossmann fold (alpha/beta folding pattern with a central beta-sheet), an NAD(P)(H)-binding region, and a structurally diverse C-terminal region. Classical SDRs are typically about 250 residues long, while extended SDRs are approximately 350 residues. Sequence identity between different SDR enzymes are typically in the 15-30% range, but the enzymes share the Rossmann fold NAD-binding motif and characteristic NAD-binding and catalytic sequence patterns. These enzymes catalyze a wide range of activities including the metabolism of steroids, cofactors, carbohydrates, lipids, aromatic compounds, and amino acids, and act in redox sensing. Classical SDRs have an TGXXX[AG]XG cofactor binding motif and a YXXXK active site motif, with the Tyr residue of the active site motif serving as a critical catalytic residue (Tyr-151, human 15-hydroxyprostaglandin dehydrogenase (15-PGDH) numbering). In addition to the Tyr and Lys, there is often an upstream Ser (Ser-138, 15-PGDH numbering) and/or an Asn (Asn-107, 15-PGDH numbering) contributing to the active site; while substrate binding is in the C-terminal region, which determines specificity. The standard reaction mechanism is a 4-pro-S hydride transfer and proton relay involving the conserved Tyr and Lys, a water molecule stabilized by Asn, and nicotinamide. Extended SDRs have additional elements in the C-terminal region, and typically have a TGXXGXXG cofactor binding motif. Complex (multidomain) SDRs such as ketoreductase domains of fatty acid synthase have a GGXGXXG NAD(P)-binding motif and an altered active site motif (YXXXN). Fungal type ketoacyl reductases have a TGXXXGX(1-2)G NAD(P)-binding motif. Some atypical SDRs have lost catalytic activity and/or have an unusual NAD(P)-binding motif and missing or unusual active site residues. Reactions catalyzed within the SDR family include isomerization, decarboxylation, epimerization, C=N bond reduction, dehydratase activity, dehalogenation, Enoyl-CoA reduction, and carbonyl-alcohol oxidoreduction.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   4 NGKVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAGVQCKAALDEQFEpQKTLFIQCDVADQQQLRDTFRKVVDHFG 83
Cdd:cd05366     1 MSKVAIITGAAQGIGRAIAERLAADGFNIVLADLNLEEAAKSTIQEISEAG-YNAVAVGADVTDKDDVEALIDQAVEKFG 79

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1391723718  84 RLDILVNNAGVN--------NEKNWEKTLQINLVSVISGTYLGLDYMSKQNGgeGGIIINMSSLAGI 142
Cdd:cd05366    80 SFDVMVNNAGIApitplltiTEEDLKKVYAVNVFGVLFGIQAAARQFKKLGH--GGKIINASSIAGV 144

clavulanic acid dehydrogenase (CAD), classical (c) SDR; CAD catalyzes the NADP-dependent reduction of clavulanate-9-aldehyde to clavulanic acid, a beta-lactamase inhibitor. SDRs are a functionally diverse family of oxidoreductases that have a single domain with a structurally conserved Rossmann fold (alpha/beta folding pattern with a central beta-sheet), an NAD(P)(H)-binding region, and a structurally diverse C-terminal region. Classical SDRs are typically about 250 residues long, while extended SDRs are approximately 350 residues. Sequence identity between different SDR enzymes are typically in the 15-30% range, but the enzymes share the Rossmann fold NAD-binding motif and characteristic NAD-binding and catalytic sequence patterns. These enzymes catalyze a wide range of activities including the metabolism of steroids, cofactors, carbohydrates, lipids, aromatic compounds, and amino acids, and act in redox sensing. Classical SDRs have an TGXXX[AG]XG cofactor binding motif and a YXXXK active site motif, with the Tyr residue of the active site motif serving as a critical catalytic residue (Tyr-151, human 15-hydroxyprostaglandin dehydrogenase (15-PGDH) numbering). In addition to the Tyr and Lys, there is often an upstream Ser (Ser-138, 15-PGDH numbering) and/or an Asn (Asn-107, 15-PGDH numbering) contributing to the active site; while substrate binding is in the C-terminal region, which determines specificity. The standard reaction mechanism is a 4-pro-S hydride transfer and proton relay involving the conserved Tyr and Lys, a water molecule stabilized by Asn, and nicotinamide. Extended SDRs have additional elements in the C-terminal region, and typically have a TGXXGXXG cofactor binding motif. Complex (multidomain) SDRs such as ketoreductase domains of fatty acid synthase have a GGXGXXG NAD(P)-binding motif and an altered active site motif (YXXXN). Fungal type ketoacyl reductases have a TGXXXGX(1-2)G NAD(P)-binding motif. Some atypical SDRs have lost catalytic activity and/or have an unusual NAD(P)-binding motif and missing or unusual active site residues. Reactions catalyzed within the SDR family include isomerization, decarboxylation, epimerization, C=N bond reduction, dehydratase activity, dehalogenation, Enoyl-CoA reduction, and carbonyl-alcohol oxidoreduction.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   5 GKVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAGVQCKAALdeQFEPQKTLFIQCDVADQQQLRDTFRKVVDHFGR 84
Cdd:cd08934     3 GKVALVTGASSGIGEATARALAAEGAAVAIAARRVDRLEALADEL--EAEGGKALVLELDVTDEQQVDAAVERTVEALGR 80

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1391723718  85 LDILVNNAGV--------NNEKNWEKTLQINLVSVISGTYLGLDYMSKQNGGEggiIINMSSLAG 141
Cdd:cd08934    81 LDILVNNAGImllgpvedADTTDWTRMIDTNLLGLMYTTHAALPHHLLRNKGT---IVNISSVAG 142

3-ketoacyl-(acyl-carrier-protein) reductase; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   1 MHVNGKVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAGVQCKAALDEQFEpQKTLFIQCDVADQQQLRDTFRKVVD 80
Cdd:PRK12825    2 GSLMGRVALVTGAARGLGRAIALRLARAGADVVVHYRSDEEAAEELVEAVEALG-RRAQAVQADVTDKAALEAAVAAAVE 80

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718  81 HFGRLDILVNNAGVN--------NEKNWEKTLQINLVSVISGTYLGLDYMSKQNGGEggiIINMSSLAGI 142
Cdd:PRK12825   81 RFGRIDILVNNAGIFedkpladmSDDEWDEVIDVNLSGVFHLLRAVVPPMRKQRGGR---IVNISSVAGL 147

mannitol dehydrogenase (MDH)-like, classical (c) SDRs; NADP-mannitol dehydrogenase catalyzes the conversion of fructose to mannitol, an acyclic 6-carbon sugar. MDH is a tetrameric member of the SDR family. This subgroup also includes various other tetrameric SDRs, including Pichia stipitis D-arabinitol dehydrogenase (aka polyol dehydrogenase), Candida albicans Sou1p, a sorbose reductase, and Candida parapsilosis (S)-specific carbonyl reductase (SCR, aka S-specific alcohol dehydrogenase) which catalyzes the enantioselective reduction of 2-hydroxyacetophenone into (S)-1-phenyl-1,2-ethanediol. SDRs are a functionally diverse family of oxidoreductases that have a single domain with a structurally conserved Rossmann fold (alpha/beta folding pattern with a central beta-sheet), an NAD(P)(H)-binding region, and a structurally diverse C-terminal region. Classical SDRs are typically about 250 residues long, while extended SDRS are approximately 350 residues. Sequence identity between different SDR enzymes are typically in the 15-30% range, but the enzymes share the Rossmann fold NAD-binding motif and characteristic NAD-binding and catalytic sequence patterns. These enzymes have a 3-glycine N-terminal NAD(P)(H)-binding pattern (typically, TGxxxGxG in classical SDRs and TGxxGxxG in extended SDRs), while substrate binding is in the C-terminal region. A critical catalytic Tyr residue (Tyr-151, human 15-hydroxyprostaglandin dehydrogenase (15-PGDH) numbering), is often found in a conserved YXXXK pattern. In addition to the Tyr and Lys, there is often an upstream Ser (Ser-138, 15-PGDH numbering) and/or an Asn (Asn-107, 15-PGDH numbering) or additional Ser, contributing to the active site. Substrates for these enzymes include sugars, steroids, alcohols, and aromatic compounds. The standard reaction mechanism is a proton relay involving the conserved Tyr and Lys, as well as Asn (or Ser).

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   5 GKVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAGVQCKAALDEQFePQKTLFIQCDVADQQQLRDTFRKVVDHFGR 84
Cdd:cd05352     8 GKVAIVTGGSRGIGLAIARALAEAGADVAIIYNSAPRAEEKAEELAKKY-GVKTKAYKCDVSSQESVEKTFKQIQKDFGK 86

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1391723718  85 LDILVNNAGVN--------NEKNWEKTLQINLvsviSGTYLGLDYMSKQ--NGGEGGIII--NMSS 138
Cdd:cd05352    87 IDILIANAGITvhkpaldyTYEQWNKVIDVNL----NGVFNCAQAAAKIfkKQGKGSLIItaSMSG 148

d-3-hydroxybutyrate dehydrogenase (HBDH), classical (c) SDRs; DHBDH, an NAD+ -dependent enzyme, catalyzes the interconversion of D-3-hydroxybutyrate and acetoacetate. It is a classical SDR, with the canonical NAD-binding motif and active site tetrad. SDRs are a functionally diverse family of oxidoreductases that have a single domain with a structurally conserved Rossmann fold (alpha/beta folding pattern with a central beta-sheet), an NAD(P)(H)-binding region, and a structurally diverse C-terminal region. Classical SDRs are typically about 250 residues long, while extended SDRs are approximately 350 residues. Sequence identity between different SDR enzymes are typically in the 15-30% range, but the enzymes share the Rossmann fold NAD-binding motif and characteristic NAD-binding and catalytic sequence patterns. These enzymes catalyze a wide range of activities including the metabolism of steroids, cofactors, carbohydrates, lipids, aromatic compounds, and amino acids, and act in redox sensing. Classical SDRs have an TGXXX[AG]XG cofactor binding motif and a YXXXK active site motif, with the Tyr residue of the active site motif serving as a critical catalytic residue (Tyr-151, human 15-hydroxyprostaglandin dehydrogenase (15-PGDH) numbering). In addition to the Tyr and Lys, there is often an upstream Ser (Ser-138, 15-PGDH numbering) and/or an Asn (Asn-107, 15-PGDH numbering) contributing to the active site; while substrate binding is in the C-terminal region, which determines specificity. The standard reaction mechanism is a 4-pro-S hydride transfer and proton relay involving the conserved Tyr and Lys, a water molecule stabilized by Asn, and nicotinamide. Extended SDRs have additional elements in the C-terminal region, and typically have a TGXXGXXG cofactor binding motif. Complex (multidomain) SDRs such as ketoreductase domains of fatty acid synthase have a GGXGXXG NAD(P)-binding motif and an altered active site motif (YXXXN). Fungal type ketoacyl reductases have a TGXXXGX(1-2)G NAD(P)-binding motif. Some atypical SDRs have lost catalytic activity and/or have an unusual NAD(P)-binding motif and missing or unusual active site residues. Reactions catalyzed within the SDR family include isomerization, decarboxylation, epimerization, C=N bond reduction, dehydratase activity, dehalogenation, Enoyl-CoA reduction, and carbonyl-alcohol oxidoreduction.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   4 NGKVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAGVQCKAALDEQFEPQKTLFIQCDVADQQQLRDTFRKVVDHFG 83
Cdd:cd08940     1 KGKVALVTGSTSGIGLGIARALAAAGANIVLNGFGDAAEIEAVRAGLAAKHGVKVLYHGADLSKPAAIEDMVAYAQRQFG 80

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1391723718  84 RLDILVNNAGVNN--------EKNWEKTLQINLVSVISGTYLGLDYMSKQNGGEggiIINMSSLAGI 142
Cdd:cd08940    81 GVDILVNNAGIQHvapiedfpTEKWDAIIALNLSAVFHTTRLALPHMKKQGWGR---IINIASVHGL 144

glucose 1 dehydrogenase (GlcDH), classical (c) SDRs; GlcDH, is a tetrameric member of the SDR family, it catalyzes the NAD(P)-dependent oxidation of beta-D-glucose to D-glucono-delta-lactone. GlcDH has a typical NAD-binding site glycine-rich pattern as well as the canonical active site tetrad (YXXXK motif plus upstream Ser and Asn). SDRs are a functionally diverse family of oxidoreductases that have a single domain with a structurally conserved Rossmann fold (alpha/beta folding pattern with a central beta-sheet), an NAD(P)(H)-binding region, and a structurally diverse C-terminal region. Classical SDRs are typically about 250 residues long, while extended SDRS are approximately 350 residues. Sequence identity between different SDR enzymes are typically in the 15-30% range, but the enzymes share the Rossmann fold NAD-binding motif and characteristic NAD-binding and catalytic sequence patterns. These enzymes have a 3-glycine N-terminal NAD(P)(H)-binding pattern (typically, TGxxxGxG in classical SDRs and TGxxGxxG in extended SDRs), while substrate binding is in the C-terminal region. A critical catalytic Tyr residue (Tyr-151, human 15-hydroxyprostaglandin dehydrogenase (15-PGDH) numbering), is often found in a conserved YXXXK pattern. In addition to the Tyr and Lys, there is often an upstream Ser (Ser-138, 15-PGDH numbering) and/or an Asn (Asn-107, 15-PGDH numbering) or additional Ser, contributing to the active site. Substrates for these enzymes include sugars, steroids, alcohols, and aromatic compounds. The standard reaction mechanism is a proton relay involving the conserved Tyr and Lys, as well as Asn (or Ser). Some SDR family members, including 17 beta-hydroxysteroid dehydrogenase contain an additional helix-turn-helix motif that is not generally found among SDRs.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   5 GKVALVTGAAQGIGRAFAEALLLKGAKVALvdwNLEAGVQCKAALDEQFEPQ--KTLFIQCDVADQQQLRDTFRKVVDHF 82
Cdd:cd05358     3 GKVALVTGASSGIGKAIAIRLATAGANVVV---NYRSKEDAAEEVVEEIKAVggKAIAVQADVSKEEDVVALFQSAIKEF 79

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1391723718  83 GRLDILVNNAGVNNE--------KNWEKTLQINLvsviSGTYLG----LDYMSKQNggEGGIIINMSS 138
Cdd:cd05358    80 GTLDILVNNAGLQGDasshemtlEDWNKVIDVNL----TGQFLCareaIKRFRKSK--IKGKIINMSS 141

bifunctional aldolase/short-chain dehydrogenase;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   5 GKVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAGVQCKAALDEQfepQKTLFIQCDVADQQQLRDTFRKVVDHFGR 84
Cdd:PRK08324  422 GKVALVTGAAGGIGKATAKRLAAEGACVVLADLDEEAAEAAAAELGGP---DRALGVACDVTDEAAVQAAFEEAALAFGG 498

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1391723718  85 LDILVNNAGV--------NNEKNWEKTLQINLvsviSGTYLGLDY----MSKQngGEGGIIINMSS 138
Cdd:PRK08324  499 VDIVVSNAGIaisgpieeTSDEDWRRSFDVNA----TGHFLVAREavriMKAQ--GLGGSIVFIAS 558

Trans-2-enoyl-CoA reductase (TER) and 2,4-dienoyl-CoA reductase (DECR), atypical (a) SDR; TTER is a peroxisomal protein with a proposed role in fatty acid elongation. Fatty acid synthesis is known to occur in the both endoplasmic reticulum and mitochondria; peroxisomal TER has been proposed as an additional fatty acid elongation system, it reduces the double bond at C-2 as the last step of elongation. This system resembles the mitochondrial system in that acetyl-CoA is used as a carbon donor. TER may also function in phytol metabolism, reducting phytenoyl-CoA to phytanoyl-CoA in peroxisomes. DECR processes double bonds in fatty acids to increase their utility in fatty acid metabolism; it reduces 2,4-dienoyl-CoA to an enoyl-CoA. DECR is active in mitochondria and peroxisomes. This subgroup has the Gly-rich NAD-binding motif of the classical SDR family, but does not display strong identity to the canonical active site tetrad, and lacks the characteristic Tyr at the usual position. SDRs are a functionally diverse family of oxidoreductases that have a single domain with a structurally conserved Rossmann fold (alpha/beta folding pattern with a central beta-sheet), an NAD(P)(H)-binding region, and a structurally diverse C-terminal region. Classical SDRs are typically about 250 residues long, while extended SDRS are approximately 350 residues. Sequence identity between different SDR enzymes are typically in the 15-30% range, but the enzymes share the Rossmann fold NAD-binding motif and characteristic NAD-binding and catalytic sequence patterns. These enzymes have a 3-glycine N-terminal NAD(P)(H)-binding pattern (typically, TGxxxGxG in classical SDRs and TGxxGxxG in extended SDRs), while substrate binding is in the C-terminal region. A critical catalytic Tyr residue (Tyr-151, human 15-hydroxyprostaglandin dehydrogenase (15-PGDH) numbering), is often found in a conserved YXXXK pattern. In addition to the Tyr and Lys, there is often an upstream Ser (Ser-138, 15-PGDH numbering) and/or an Asn (Asn-107, 15-PGDH numbering) or additional Ser, contributing to the active site. Substrates for these enzymes include sugars, steroids, alcohols, and aromatic compounds. The standard reaction mechanism is a proton relay involving the conserved Tyr and Lys, as well as Asn (or Ser). Some SDR family members, including 17 beta-hydroxysteroid dehydrogenase contain an additional helix-turn-helix motif that is not generally found among SDRs.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1391723718   5 GKVALVTGAAQGIGRAFAEALLLKGAKVALVDWNLEAGVQCKAALdEQFEPQKTLFIQCDVADQQQLRDTFRKVVDHFGR 84
Cdd:cd05369     3 GKVAFITGGGTGIGKAIAKAFAELGASVAIAGRKPEVLEAAAEEI-SSATGGRAHPIQCDVRDPEAVEAAVDETLKEFGK 81

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1391723718  85 LDILVNNAGVN--------NEKNWEKTLQINLVsvisGTYlgldYMSKQNG------GEGGIIINMSS 138
Cdd:cd05369    82 IDILINNAAGNflapaeslSPNGFKTVIDIDLN----GTF----NTTKAVGkrlieaKHGGSILNISA 141