Dissimilatory sulfite reductase (desulfoviridin), alpha and beta subunits [Inorganic ion transport and metabolism];

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*..
gi 446169925  28 ACADVCPAQAFSLAQGQVSIDTTRCIACGDCLFVCPVDAITGIKPVK 74
Cdd:COG2221   22 LCVAVCPTGAISLDDGKLVIDEEKCIGCGACIRVCPTGAIKGEKPKK 68

Dissimilatory sulfite reductase (desulfoviridin), alpha and beta subunits [Inorganic ion transport and metabolism];

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*..
gi 446169925  28 ACADVCPAQAFSLAQGQVSIDTTRCIACGDCLFVCPVDAITGIKPVK 74
Cdd:COG2221   22 LCVAVCPTGAISLDDGKLVIDEEKCIGCGACIRVCPTGAIKGEKPKK 68

archaeoflavoprotein, MJ0208 family; This model describes one of two paralogous families of archaealflavoprotein. The other, described by TIGR02699 and typified by the partially characterized AF1518 of Archaeoglobus fulgidus, is a homodimeric FMN-containing flavoprotein that accepts electrons from ferredoxin and can transfer them to various oxidoreductases. The function of this protein family is unknown. [Unknown function, General]

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 446169925  162 ITPCAVEPGKRRLRQAFSafsecvpeISPQECRMCGACWRSCPENVIQFDDNTLTIAAARCTGCGGCAAVCPHQALRLRF 241
Cdd:TIGR02700 127 VVPVDYEEGIIRTITPYM--------IDRKRCKGCGICVDACPRSAIDMVDGKAFIRLLKCVGCGKCKEACPYNAIHGGL 198

                  ...
gi 446169925  242 DVE 244
Cdd:TIGR02700 199 EYE 201

NapF, iron-sulfur subunit of periplasmic nitrate reductase; This family contains NapF protein, the iron-sulfur subunit of periplasmic nitrate reductase. The periplasmic nitrate reductase NapABC of Escherichia coli likely functions during anaerobic growth in low-nitrate environments; napF operon expression is activated by cyclic AMP receptor protein (Crp). NapF is a subfamily of the beta subunit of DMSO reductase (DMSOR) family. DMSOR family members have a large, periplasmic molybdenum-containing alpha subunit as well as a small beta FeS subunit, and may also have a small gamma subunit. The beta subunit contains four Fe4/S4 and/or Fe3/S4 clusters which transfer the electrons from the alpha subunit to a hydrophobic integral membrane protein, presumably a cytochrome containing two b-type heme groups. The reducing equivalents are then transferred to menaquinone, which finally reduces the electron-accepting enzyme system.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 446169925 191 QECRMCGACWRSCPENVIQFDDN---TLTIAAARCTGCGGCAAVCPHQALRLRfdvEPASTRHSAAHTLTC 258
Cdd:cd10564   13 DLCTRCGDCVEACPEGIIVRGDGgfpELDFSRGECTFCGACAEACPEGALDPA---REAPWPLRAEIGDSC 80

4Fe-4S dicluster domain; Superfamily includes proteins containing domains which bind to iron-sulfur clusters. Members include bacterial ferredoxins, various dehydrogenases, and various reductases. Structure of the domain is an alpha-antiparallel beta sandwich. Domain contains two 4Fe4S clusters.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 446169925  193 CRMCGACWRSCPENVIQFDD-------NTLTIAAARCTGCGGCAAVCPHQA 236
Cdd:pfam12838   1 CIGCGACVAACPVGAITLDEvgekkgtKTVVIDPERCVGCGACVAVCPTGA 51

4Fe-4S dicluster domain; Superfamily includes proteins containing domains which bind to iron-sulfur clusters. Members include bacterial ferredoxins, various dehydrogenases, and various reductases. Structure of the domain is an alpha-antiparallel beta sandwich. Domain contains two 4Fe4S clusters.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 446169925   28 ACADVCPAQAFSLA-------QGQVSIDTTRCIACGDCLFVCPVDA 66
Cdd:pfam12838   6 ACVAACPVGAITLDevgekkgTKTVVIDPERCVGCGACVAVCPTGA 51

Iron only hydrogenase large subunit, C-terminal domain [Energy production and conversion];

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 446169925 184 CVPEISPQECRMCGACWRSCPENVIQFDDNTLTIAAARCTGCGGCAAVCPHQALRLRFDVEP 245
Cdd:COG4624   84 PSIIRDKEKCKNCYPCVRACPVKAIKVDDGKAEIDEEKCISCGQCVAVCPFGAITEKSDIEK 145

Uncharacterized Fe-S cluster protein [Function unknown];

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 446169925 186 PEISPQECRMCGACWRSCPENVIQFDDNTLTIAAARCTGCGGCAAVCPHQALRLRFDVEPA 246
Cdd:COG2768    6 PYVDEEKCIGCGACVKVCPVGAISIEDGKAVIDPEKCIGCGACIEVCPVGAIKIEWEEDEE 66

Dissimilatory sulfite reductase (desulfoviridin), alpha and beta subunits [Inorganic ion transport and metabolism];

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 446169925 186 PEISPQECRMCGACWRSCPENVIQFDDNTLTIAAARCTGCGGCAAVCPHQALRLR 240
Cdd:COG2221   10 PKIDEEKCIGCGLCVAVCPTGAISLDDGKLVIDEEKCIGCGACIRVCPTGAIKGE 64

Dissimilatory sulfite reductase (desulfoviridin), alpha and beta subunits [Inorganic ion transport and metabolism];

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*..
gi 446169925  28 ACADVCPAQAFSLAQGQVSIDTTRCIACGDCLFVCPVDAITGIKPVK 74
Cdd:COG2221   22 LCVAVCPTGAISLDDGKLVIDEEKCIGCGACIRVCPTGAIKGEKPKK 68

TPP-dependent indolepyruvate ferredoxin oxidoreductase, alpha subunit [Energy production and conversion];

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 446169925  28 ACADVCPAQAFSLAQGQVSIDTTRCIACGDCLFVCPVDAITGIKPVKR 75
Cdd:COG4231   29 ACVKVCPADAIEEGDGKAVIDPDLCIGCGSCVQVCPVDAIKLEKRVPE 76

NAD-dependent dihydropyrimidine dehydrogenase, PreA subunit [Nucleotide transport and metabolism];

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 446169925 186 PEISPQECRMCGACWRSCPENVIQFDDNTLTIAAAR---CTGCGGCAAVCPHQALRLRFDVE 244
Cdd:COG1146    3 PVIDTDKCIGCGACVEVCPVDVLELDEEGKKALVINpeeCIGCGACELVCPVGAITVEDDEP 64

hydrogenase 4 subunit H; Validated

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 446169925 186 PEISPQECRMCGACWRSCPENV------IQFDDNTLTIAAARCTGCGGCAAVCPHQALRLRFDVEPASTRHSAAHTltcd 259
Cdd:PRK08222  33 PDLMPSQCIACGACTCACPANAltiqtdDQQNSRTWQLYLGRCIYCGRCEEVCPTRAIQLTNNFELTVTNKADLYT---- 108

                         90       100
                 ....*....|....*....|..
gi 446169925 260 icKRTFHALtpehtHCVLCQSP 281
Cdd:PRK08222 109 --RATFHLQ-----RCSRCERP 123

archaeoflavoprotein, MJ0208 family; This model describes one of two paralogous families of archaealflavoprotein. The other, described by TIGR02699 and typified by the partially characterized AF1518 of Archaeoglobus fulgidus, is a homodimeric FMN-containing flavoprotein that accepts electrons from ferredoxin and can transfer them to various oxidoreductases. The function of this protein family is unknown. [Unknown function, General]

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|
gi 446169925   29 CADVCPAQAFSLAQGQVSIDTTRCIACGDCLFVCPVDAITGIKPVKRFVQ 78
Cdd:TIGR02700 156 CVDACPRSAIDMVDGKAFIRLLKCVGCGKCKEACPYNAIHGGLEYEMRVR 205

Fe-S-cluster-containing hydrogenase component 2 [Energy production and conversion];

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 446169925 190 PQECRMC--GACWRSCPENVIQFDDNTLTIAAARCTGCGGCAAVCPHQALRLRfdvepasTRHSAAHTLTCDICK 262
Cdd:COG1142   49 PVQCRHCedAPCAEVCPVGAITRDDGAVVVDEEKCIGCGLCVLACPFGAITMV-------GEKSRAVAVKCDLCG 116

Formate hydrogenlyase subunit 6/NADH:ubiquinone oxidoreductase 23 kD subunit (chain I) [Energy production and conversion]; Formate hydrogenlyase subunit 6/NADH:ubiquinone oxidoreductase 23 kD subunit (chain I) is part of the Pathway/BioSystem: NADH dehydrogenase

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 446169925 190 PQECRMCGACWRSCPENVIQFDDN----TLTIAAARCTGCGGCAAVCPHQALRLRFDVEPASTRH 250
Cdd:COG1143    1 EDKCIGCGLCVRVCPVDAITIEDGepgkVYVIDPDKCIGCGLCVEVCPTGAISMTPFELAVEDRE 65

NapF, iron-sulfur subunit of periplasmic nitrate reductase; This family contains NapF protein, the iron-sulfur subunit of periplasmic nitrate reductase. The periplasmic nitrate reductase NapABC of Escherichia coli likely functions during anaerobic growth in low-nitrate environments; napF operon expression is activated by cyclic AMP receptor protein (Crp). NapF is a subfamily of the beta subunit of DMSO reductase (DMSOR) family. DMSOR family members have a large, periplasmic molybdenum-containing alpha subunit as well as a small beta FeS subunit, and may also have a small gamma subunit. The beta subunit contains four Fe4/S4 and/or Fe3/S4 clusters which transfer the electrons from the alpha subunit to a hydrophobic integral membrane protein, presumably a cytochrome containing two b-type heme groups. The reducing equivalents are then transferred to menaquinone, which finally reduces the electron-accepting enzyme system.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....
gi 446169925 192 ECRMCGacwRSCPENVIQFDDNTLTIA-----AARCTGCGGCAAVCPHQALRLR 240
Cdd:cd10564   87 ECRSCQ---DACPTQAIRFRPRLGGIAlpeldADACTGCGACVSVCPVGAITLT 137

Formate hydrogenlyase subunit 6/NADH:ubiquinone oxidoreductase 23 kD subunit (chain I) [Energy production and conversion]; Formate hydrogenlyase subunit 6/NADH:ubiquinone oxidoreductase 23 kD subunit (chain I) is part of the Pathway/BioSystem: NADH dehydrogenase

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 446169925  28 ACADVCPAQAFSLAQGQVS----IDTTRCIACGDCLFVCPVDAIT 68
Cdd:COG1143    9 LCVRVCPVDAITIEDGEPGkvyvIDPDKCIGCGLCVEVCPTGAIS 53

Ferredoxin [Energy production and conversion];

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 446169925  28 ACADVCPAQAFSLAQG--QVSIDTTRCIACGDCLFVCPVDAIT 68
Cdd:COG1145  189 LCVKVCPTGAIRLKDGkpQIVVDPDKCIGCGACVKVCPVGAIS 231

NapF, iron-sulfur subunit of periplasmic nitrate reductase; This family contains NapF protein, the iron-sulfur subunit of periplasmic nitrate reductase. The periplasmic nitrate reductase NapABC of Escherichia coli likely functions during anaerobic growth in low-nitrate environments; napF operon expression is activated by cyclic AMP receptor protein (Crp). NapF is a subfamily of the beta subunit of DMSO reductase (DMSOR) family. DMSOR family members have a large, periplasmic molybdenum-containing alpha subunit as well as a small beta FeS subunit, and may also have a small gamma subunit. The beta subunit contains four Fe4/S4 and/or Fe3/S4 clusters which transfer the electrons from the alpha subunit to a hydrophobic integral membrane protein, presumably a cytochrome containing two b-type heme groups. The reducing equivalents are then transferred to menaquinone, which finally reduces the electron-accepting enzyme system.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 446169925  28 ACADVCPAQA--FSLAQGQV---SIDTTRCIACGDCLFVCPVDAIT 68
Cdd:cd10564   90 SCQDACPTQAirFRPRLGGIalpELDADACTGCGACVSVCPVGAIT 135

HycB, HydN and similar proteins; This family includes HycB, the FeS subunit of a membrane-associated formate hydrogenlyase system (FHL-1) in Escherichia coli that breaks down formate, produced during anaerobic fermentation, to H2 and CO2. FHL-1 consists of formate dehydrogenase H (FDH-H) and the hydrogenase 3 complex (Hyd-3). HycB is thought to code for the [4Fe-4S] ferredoxin subunit of hydrogenase 3, which functions as an intermediate electron carrier protein between hydrogenase 3 and formate dehydrogenase. HydN codes for the [4Fe-4S] ferredoxin subunit of FDH-H; a hydN in-frame deletion mutation causes only weak reduction in hydrogenase activity, but loss of more than 60% of FDH-H activity. This pathway is only active at low pH and high formate concentrations, and is thought to provide a detoxification/de-acidification system countering the buildup of formate during fermentation.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 446169925 190 PQECRMC--GACWRSCPENVIQFDDNTLTIAAARCTGCGGCAAVCPHQALRLRFDVEPASTRHSAAHTLT--CDIC 261
Cdd:cd10554   53 PVQCRQCedAPCANVCPVGAISQEDGVVQVDEERCIGCKLCVLACPFGAIEMAPTTVPGVDWERGPRAVAvkCDLC 128

4Fe-4S dicluster domain; Superfamily includes proteins containing domains which bind to iron-sulfur clusters. Members include bacterial ferredoxins, various dehydrogenases, and various reductases. Structure of the domain is an alpha-antiparallel beta sandwich. Domain contains two 4Fe4S clusters.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 446169925  193 CRMCGACWRSCPENVIQFDD-------NTLTIAAARCTGCGGCAAVCPHQA 236
Cdd:pfam12838   1 CIGCGACVAACPVGAITLDEvgekkgtKTVVIDPERCVGCGACVAVCPTGA 51

glycine radical enzyme activase, YjjW family; Members of this family are radical SAM enzymes, designated YjjW in E. coli, that are paired with and appear to activate a glycyl radical enzyme of unknown function, designated YjjI. This activase and its target are found in Clostridial species as well as E. coli and cousins. Members of this family may be misannotated as pyruvate formate lyase activating enzyme. [Protein fate, Protein modification and repair]

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 446169925   28 ACADVCPAQAFSLAQGQVSIDTTRCIACGDCLFVCP-----------VDAITG-IKPVKRFVQGDTLV-GPFSLQAPTVD 94
Cdd:TIGR04041  48 DCVAGCPAGALSLVDGKVVWDKERCIGCDTCIKVCPhqsspktkeytVEELLDrIRKNMPFIRGITVSgGECTLQLDFLT 127

                  ..
gi 446169925   95 EL 96
Cdd:TIGR04041 128 EL 129

pyruvate ferredoxin oxidoreductase subunit gamma/delta; Provisional

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 446169925 186 PEISPQECRMCGACWRSCPENVI-------------QFDDNTLTIAAARCTGCGGCAAVCPHQALRL 239
Cdd:PRK14028 242 PVIDHSKCIMCRKCWLYCPDDAIieawreaegprgrKFRMKMIDFDYQYCKGCGVCAEVCPTGAIQM 308

hypothetical protein; Provisional

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 446169925 191 QECRMCGACWRSCPENVIQFDDNTLTIA--AARCTGCGGCAAVCP 233
Cdd:PRK13795 581 AECVGCGVCVGACPTGAIRIEEGKRKISvdEEKCIHCGKCTEVCP 625

uncharacterized subfamily of DMSO Reductase beta subunit family; This family consists of the small beta iron-sulfur (FeS) subunit of the DMSO Reductase (DMSOR) family. Members of this family also contain a large, periplasmic molybdenum-containing alpha subunit and may have a small gamma subunit as well. Examples of heterodimeric members with alpha and beta subunits include arsenite oxidase, and tungsten-containing formate dehydrogenase (FDH-T) while heterotrimeric members containing alpha, beta, and gamma subunits include formate dehydrogenase-N (FDH-N), and nitrate reductase (NarGHI). The beta subunit contains four Fe4/S4 and/or Fe3/S4 clusters which transfer the electrons from the alpha subunit to a hydrophobic integral membrane protein, presumably a cytochrome containing two b-type heme groups. The reducing equivalents are then transferred to menaquinone, which finally reduces the electron-accepting enzyme system.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 446169925 158 PRDAITPCAVEPGKRRLRQAFSAFSECVPEispQECRMCGACWRSCP--ENVIQFDDNTL--TIAAARCTGCGGCAAVCP 233
Cdd:cd16373   67 PTGALRPLDLEEQKVKMGVAVIDKDRCLAW---QGGTDCGVCVEACPteAIAIVLEDDVLrpVVDEDKCVGCGLCEYVCP 143

NADH-quinone oxidoreductase subunit NuoI;

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 446169925  29 CADVCPAQAFSLAQGQV----------SIDTTRCIACGDCLFVCPVDAIT 68
Cdd:PRK05888  66 CAAICPADAITIEAAERedgrrrttryDINFGRCIFCGFCEEACPTDAIV 115

Fe-S cluster domain-containing protein;

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 446169925 193 CRMCGACWRSCPENVIQFDDNTLTIAAARCTGCGGCAAVCPHQALRLR 240
Cdd:PRK07118 215 CIGCGKCVKACPAGAITMENNLAVIDQEKCTSCGKCVEKCPTKAIRIL 262

Fe-S-cluster-containing dehydrogenase component (DMSO reductase) [Energy production and conversion];

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|.
gi 446169925  28 ACADVCPAQAFS-LAQGQVSIDTTRCIACGDCLFVCPVDAI 67
Cdd:COG0437   67 PCVKVCPTGATYkREDGIVLVDYDKCIGCRYCVAACPYGAP 107

ferredoxin-type protein NapF; The gene codes for a ferredoxin-type cytosolic protein, NapF, of the periplasmic nitrate reductase system, as in Escherichia coli. NapF interacts with the catalytic subunit, NapA, and may be an accessory protein for NapA maturation. [Energy metabolism, Electron transport]

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 446169925  193 CRMCGACWRSCPENVIQFDDN---TLTIAAARCTGCGGCAAVCPHQALRLRF 241
Cdd:TIGR00402  36 CTRCGECASACENNILQLGQQgqpTVEFDNAECDFCGKCAEACPTNAFHPRF 87

NADH-quinone oxidoreductase, chain I; This model represents the I subunit (one of 14: A->N) of the NADH-quinone oxidoreductase complex I which generally couples NADH and ubiquinone oxidation/reduction in bacteria and mammalian mitochondria, but may act on NADPH and/or plastoquinone in cyanobacteria and plant chloroplasts. This model excludes "I" subunits from the closely related F420H2 dehydrogenase and formate hydrogenlyase complexes. [Energy metabolism, Electron transport]

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 446169925   29 CADVCPAQAFSL--AQGQV--------SIDTTRCIACGDCLFVCPVDAI 67
Cdd:TIGR01971  51 CAAVCPADAIRVvpAEGEDgkrrlkfyEINFGRCIFCGLCEEACPTDAI 99

Uncharacterized polyferredoxin-like protein; This family contains uncharacterized polyferredoxin protein similar to Methanobacterium thermoautotrophicum MvhB. The mvhB is a gene of the methylviologen-reducing hydrogenase operon. It is predicted to contain 12 [4Fe-4S] clusters, and was therefore suggested to be a polyferredoxin. As a subfamily of the beta subunit of the DMSO Reductase (DMSOR) family, it is predicted to function as electron carrier in the reducing reaction.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 446169925 186 PEISPQECRMCGACWRSCPENVIQFDDNTLTIAAA---------RCTGCGGCAAVCPHQALRLRFDVEP 245
Cdd:cd10549   35 PEIDEDKCVFCGACVEVCPTGAIELTPEGKEYVPKekeaeideeKCIGCGLCVKVCPVDAITLEDELEI 103

Beta subunit of the DMSO Reductase (DMSOR) family; This family consists of the small beta iron-sulfur (FeS) subunit of the DMSO Reductase (DMSOR) family. Members of this family also contain a large, periplasmic molybdenum-containing alpha subunit and may have a small gamma subunit as well. Examples of heterodimeric members with alpha and beta subunits include arsenite oxidase, and tungsten-containing formate dehydrogenase (FDH-T) while heterotrimeric members containing alpha, beta, and gamma subunits include formate dehydrogenase-N (FDH-N), and nitrate reductase (NarGHI). The beta subunit contains four Fe4/S4 and/or Fe3/S4 clusters which transfer the electrons from the alpha subunit to a hydrophobic integral membrane protein, presumably a cytochrome containing two b-type heme groups. The reducing equivalents are then transferred to menaquinone, which finally reduces the electron-accepting enzyme system.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|.
gi 446169925  28 ACADVCPAQAFSL-AQGQVSIDTTRCIACGDCLFVCPVDAI 67
Cdd:cd04410   57 PCVKACPTGAIYKdEDGIVLIDEDKCIGCGSCVEACPYGAI 97

uncharacterized subfamily of DMSO Reductase beta subunit family; This family consists of the small beta iron-sulfur (FeS) subunit of the DMSO Reductase (DMSOR) family. Members of this family also contain a large, periplasmic molybdenum-containing alpha subunit and may have a small gamma subunit as well. Examples of heterodimeric members with alpha and beta subunits include arsenite oxidase, and tungsten-containing formate dehydrogenase (FDH-T) while heterotrimeric members containing alpha, beta, and gamma subunits include formate dehydrogenase-N (FDH-N), and nitrate reductase (NarGHI). The beta subunit contains four Fe4/S4 and/or Fe3/S4 clusters which transfer the electrons from the alpha subunit to a hydrophobic integral membrane protein, presumably a cytochrome containing two b-type heme groups. The reducing equivalents are then transferred to menaquinone, which finally reduces the electron-accepting enzyme system.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 446169925  28 ACADVCPAQAFSL--AQGQVSIDTTRCIACGDCLFVCPVDAITGI 70
Cdd:cd10550   56 PCVEACPVGAISRdeETGAVVVDEDKCIGCGMCVEACPFGAIRVD 100

NAD-dependent dihydropyrimidine dehydrogenase, PreA subunit [Nucleotide transport and metabolism];

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....
gi 446169925  28 ACADVCPAQAFSLAQGQVS---IDTTRCIACGDCLFVCPVDAIT 68
Cdd:COG1146   15 ACVEVCPVDVLELDEEGKKalvINPEECIGCGACELVCPVGAIT 58

4Fe-4S dicluster domain; This family includes proteins containing domains which bind to iron-sulfur clusters. Members include bacterial ferredoxins, various dehydrogenases, and various reductases. The structure of the domain is an alpha-antiparallel beta sandwich.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 446169925  186 PEISPQECRMCGACWRSCPEN-------VIQFDDNTLTIAAARCTGCGGCAAVCP 233
Cdd:pfam13237   2 VVIDPDKCIGCGRCTAACPAGltrvgaiVERLEGEAVRIGVWKCIGCGACVEACP 56

Heterodisulfide reductase, subunit A (polyferredoxin) [Energy production and conversion];

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 446169925  28 ACADVCPAQAFSLAQGQVS-IDTTRCIACGDCLFVCPVDAIT 68
Cdd:COG1148  503 RCVEVCPYGAISIDEKGVAeVNPALCKGCGTCAAACPSGAIS 544

pyruvate:ferredoxin (flavodoxin) oxidoreductase, homodimeric; This model represents a single chain form of pyruvate:ferredoxin (or flavodoxin) oxidoreductase. This enzyme may transfer electrons to nitrogenase in nitrogen-fixing species. Portions of this protein are homologous to gamma subunit of the four subunit pyruvate:ferredoxin (flavodoxin) oxidoreductase.

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 446169925   185 VPEISPQECRMCGACWRSCPENVIQ---FDDNTLTIAAAR------------------------CTGCGGCAAVCP 233
Cdd:TIGR02176  677 VPVWVPDNCIQCNQCAFVCPHAAIRpklADEEELENAPAGfksldakgkelegmkfriqispldCTGCGNCVDICP 752

uncharacterized subfamily of beta subunit of formate dehydrogenase; This subfamily includes the beta-subunit of formate dehydrogenases that are as yet uncharacterized. Members of the DMSO reductase family include formate dehydrogenase N and O (FDH-N, FDH-O) and tungsten-containing formate dehydrogenase (W-FDH) and other similar proteins. FDH-N, a major component of nitrate respiration of Escherichia coli, is involved in the major anaerobic respiratory pathway in the presence of nitrate, catalyzing the oxidation of formate to carbon dioxide at the expense of nitrate reduction to nitrite. It forms a heterotrimer; the alpha-subunit (FDH-G) is the catalytic site of formate oxidation and membrane-associated, incorporating a selenocysteine (SeCys) residue and a [4Fe/4S] cluster in addition to two bis-MGD cofactors, the beta subunit (FDH-H) contains four [4Fe/4S] clusters which transfer the electrons from the alpha subunit to the gamma-subunit (FDH-I), a hydrophobic integral membrane protein, presumably a cytochrome containing two b-type heme groups. W-FDH contains a tungsten instead of molybdenum at the catalytic center. This enzyme seems to be exclusively found in organisms such as hyperthermophilic archaea that live in extreme environments. It is a heterodimer of a large and a small subunit; the large subunit harbors the W site and one [4Fe-4S] center and the small subunit, containing three [4Fe-4S] clusters, functions to transfer electrons.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|.
gi 446169925  28 ACADVCPAQA-FSLAQGQVSIDTTRCIACGDCLFVCPVDAI 67
Cdd:cd10562   77 ACVKVCPTGAlYKTENGAVVVDEDKCIGCGYCVAACPFDVP 117

putative oxidoreductase Fe-S binding subunit; Reviewed

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 446169925 193 CRMC--GACWRSCPENVIQFDDNTLTIAAARCTGCGGCAAVCPHQALRLRFDVEPASTRHSAAHtlTCDIC 261
Cdd:PRK12769  56 CHHCedAPCARSCPNGAISHVDDSIQVNQQKCIGCKSCVVACPFGTMQIVLTPVAAGKVKATAH--KCDLC 124

polysulfide reductase beta (PsrB) subunit; This family includes the beta subunit of bacterial polysulfide reductase (PsrABC), an integral membrane-bound enzyme responsible for quinone-coupled reduction of polysulfides, a process important in extreme environments such as deep-sea vents and hot springs. Polysulfide reductase contains three subunits: a catalytic subunit PsrA, an electron transfer PsrB subunit and the hydrophobic transmembrane PsrC subunit. PsrB belongs to the DMSO reductase superfamily that contains [4Fe-4S] clusters which transfer the electrons from the A subunit to the hydrophobic integral membrane C subunit via the B subunit. In Shewanella oneidensis, which has highly diverse anaerobic respiratory pathways, PsrABC is responsible for H2S generation as well as its regulation via respiration of sulfur species. PsrB transfers electrons from PsrC (serving as quinol oxidase) to the catalytic subunit PsrA for reduction of corresponding electron acceptors. It has been shown that T. thermophilus polysulfide reductase could be a key energy-conserving enzyme of the respiratory chain, using polysulfide as the terminal electron acceptor and pumping protons across the membrane.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 446169925  28 ACADVCPAQA-FSLAQGQVSIDTTRCIACGDCLFVCPVDAIT 68
Cdd:cd10551   60 PCVKVCPTGAtYKREDGIVLVDYDKCIGCRYCMAACPYGARY 101

uncharacterized subfamily of DMSO Reductase beta subunit family; This family consists of the small beta iron-sulfur (FeS) subunit of the DMSO Reductase (DMSOR) family. Members of this family also contain a large, periplasmic molybdenum-containing alpha subunit and may have a small gamma subunit as well. Examples of heterodimeric members with alpha and beta subunits include arsenite oxidase, and tungsten-containing formate dehydrogenase (FDH-T) while heterotrimeric members containing alpha, beta, and gamma subunits include formate dehydrogenase-N (FDH-N), and nitrate reductase (NarGHI). The beta subunit contains four Fe4/S4 and/or Fe3/S4 clusters which transfer the electrons from the alpha subunit to a hydrophobic integral membrane protein, presumably a cytochrome containing two b-type heme groups. The reducing equivalents are then transferred to menaquinone, which finally reduces the electron-accepting enzyme system.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|.
gi 446169925  29 CADVCPAQAFSL-AQGQVSIDTTRCIACGDCLFVCPVDAIT 68
Cdd:cd16374   51 CMEVCPTGAIYRdEDGAVLVDPDKCIGCGMCAMACPFGVPR 91