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        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1840641109  61 GLGVALSQLFREPATINYPFEKGPLSPRFRGEHALRRYPSGEERCIACKLCEAICPAQAITIEAEERADGSRRTTRYDID 140
Cdd:TIGR01971   1 GLGLTLKYFFSKPVTVQYPEEKLYLPPRFRGRIVLTRDPNGEEKCIGCTLCAAVCPADAIRVVPAEGEDGKRRLKFYEIN 80

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|..
gi 1840641109 141 MSKCIYCGFCQEACPVDAIVEGPNFEFSTETHEEMLYNKEKL 182
Cdd:TIGR01971  81 FGRCIFCGLCEEACPTDAIVLTPEFELATYTRSDLVYGKEDL 122

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
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1840641109 102 EERCIACKLCEAICPAQAITIEAEERADgsrrttrydIDMSKCIYCGFCQEACPVDAIV 160
Cdd:cd10549    77 EEKCIGCGLCVKVCPVDAITLEDELEIV---------IDKEKCIGCGICAEVCPVNAIK 126

EFR1 family ferrodoxin; Members of the family have a C-terminal ferrodoxin domain, with eight conserved Cys residues in two CxxCxxCxxxCP motifs, each of which binds a 4Fe-4S cluster. The N-terminal region resembles flavodoxin domains, with some members of the family recognized by Pfam models PF12724 (Flavodoxin_5) or PF00258 (Flavodoxin_1).

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1840641109  68 QLFREPATINYPFEKGPLSPRFRGEHALRRYPSGEERCIACKLCEAICPAQAITIEaEERAdgsrrttrydIDMSKCIYC 147
Cdd:NF038196  150 KGPEKKKGFIPRLLSKLVNPLFYKFKVKDKKFHVTDKCIGCGICAKVCPVNNIEME-DGKP----------VWGHNCTHC 218

                          90
                  ....*....|..
gi 1840641109 148 GFCQEACPVDAI 159
Cdd:NF038196  219 LACIHRCPKEAI 230

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        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1840641109  61 GLGVALSQLFREPATINYPFEKGPLSPRFRGEHALRRYPSGEERCIACKLCEAICPAQAITIEAEERADGSRRTTRYDID 140
Cdd:TIGR01971   1 GLGLTLKYFFSKPVTVQYPEEKLYLPPRFRGRIVLTRDPNGEEKCIGCTLCAAVCPADAIRVVPAEGEDGKRRLKFYEIN 80

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|..
gi 1840641109 141 MSKCIYCGFCQEACPVDAIVEGPNFEFSTETHEEMLYNKEKL 182
Cdd:TIGR01971  81 FGRCIFCGLCEEACPTDAIVLTPEFELATYTRSDLVYGKEDL 122

formate hydrogenlyase complex iron-sulfur subunit; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1840641109  73 PATINYPFEKGPLSPRFRG--EHALrrypsgeERCIACKLCEAICPAQAITIEAEERADgsrrTTRYDIDMSKCIYCGFC 150
Cdd:PRK12387   13 TATSSYPLEPIAVDKNFRGkpEYNP-------QQCIGCAACVNACPSNALTVETDLATG----ELAWEFNLGRCIFCGRC 81

                          90       100       110
                  ....*....|....*....|....*....|
gi 1840641109 151 QEACPVDAIVEGPNFEFSTETHEEMLYNKE 180
Cdd:PRK12387   82 EEVCPTAAIKLSQEFELAVWKKEDLLQQSE 111

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
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1840641109 102 EERCIACKLCEAICPAQAITIEAEERADgsrrttrydIDMSKCIYCGFCQEACPVDAIV 160
Cdd:cd10549    77 EEKCIGCGLCVKVCPVDAITLEDELEIV---------IDKEKCIGCGICAEVCPVNAIK 126

Uncharacterized Fe-S cluster protein [Function unknown];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1840641109  93 HALRRYPSGEERCIACKLCEAICPAQAITIEAEeradgsrrttRYDIDMSKCIYCGFCQEACPVDAIVegPNFEFSTETH 172
Cdd:COG2768     1 HSLGKPYVDEEKCIGCGACVKVCPVGAISIEDG----------KAVIDPEKCIGCGACIEVCPVGAIK--IEWEEDEEFQ 68

                  ...
gi 1840641109 173 EEM 175
Cdd:COG2768    69 EKM 71

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        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1840641109 102 EERCIACKLCEAICPAQAITIEAEERAdgsrrTTRYDIDMSKCIYCGFCQEACPVDAIVEGPNFEFSTETHEEMLYNKEK 181
Cdd:cd10549     5 PEKCIGCGICVKACPTDAIELGPNGAI-----ARGPEIDEDKCVFCGACVEVCPTGAIELTPEGKEYVPKEKEAEIDEEK 79

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
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1840641109 102 EERCIACKLCEAICPAQAITIEaEERADGSRRTTRYDIDMSKCIYCGFCQEACPVDAI 159
Cdd:cd10549    39 EDKCVFCGACVEVCPTGAIELT-PEGKEYVPKEKEAEIDEEKCIGCGLCVKVCPVDAI 95

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

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1840641109 102 EERCIACKLCEAICPAQAITIEaeeraDGSRRttrydIDMSKCIYCGFCQEACPVDAIV 160
Cdd:COG4231    21 EDKCTGCGACVKVCPADAIEEG-----DGKAV-----IDPDLCIGCGSCVQVCPVDAIK 69

Ferredoxin [Energy production and conversion];

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1840641109 102 EERCIACKLCEAICPAQAITIEAEERAdgsrrttrYDIDMSKCIYCGFCQEACPVDAI 159
Cdd:COG1145   181 AEKCIGCGLCVKVCPTGAIRLKDGKPQ--------IVVDPDKCIGCGACVKVCPVGAI 230

NADH-plastoquinone oxidoreductase subunit; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1840641109  62 LGVALSQLFREPATINYP-FEKGPLSPRFRGEHALRRypsgeERCIACKLCEAICPAQAITIEAEERadgsrrttRYDID 140
Cdd:PRK08348    5 LPTVLRNLFKKPATNLFPaTEPVPVPEDFRGKILYDV-----DKCVGCRMCVTVCPAGVFVYLPEIR--------KVALW 71

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|.
gi 1840641109 141 MSKCIYCGFCQEACPVDAIVEGPNFEFSTETH--EEMLYNK 179
Cdd:PRK08348   72 TGRCVFCGQCVDVCPTGALQMSDDFLLASYDRfdEKFIPLK 112

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

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1840641109 102 EERCIACKLCEAICPAQAITIEaEERADgsrrttrydIDMSKCIYCGFCQEACPVDAIVEgpnfefSTETHE--EMLYNK 179
Cdd:COG4624    90 KEKCKNCYPCVRACPVKAIKVD-DGKAE---------IDEEKCISCGQCVAVCPFGAITE------KSDIEKvkKALKDP 153

                  ..
gi 1840641109 180 EK 181
Cdd:COG4624   154 EK 155

4Fe-4S dicluster domain;

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1840641109 104 RCIACKLCEAICPAQAITIeaeeraDGSRRTTRYDIDMSKCIYCGFCQEACPVDAI 159
Cdd:pfam13187   1 KCTGCGACVAACPAGAIVP------DLVGQTIRGDIAGLACIGCGACVDACPRGAI 50

[FeFe] hydrogenase, group B1/B3; See for descriptions of different groups.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1840641109 103 ERCIACKLC----------------EAICPAQAITIEAEERADgsrrttrydIDMSKCIYCGFCQEACPVDAIVE 161
Cdd:TIGR04105 142 EKCIECGKCkkacpynaiveierpcEKACPVGAISSDEDGRAV---------IDYDKCISCGACMVACPFGAISD 207

ferredoxin; Provisional

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1840641109 102 EERCIACKLCEAICPAQAIT---IEAEERADGSRRTTRYDIDMSKCIYCGFCQEACPV 156
Cdd:PRK06273   48 EELCIGCGGCANVCPTKAIEmipVEPVKITEGYVKTKIPKIDYEKCVYCLYCHDFCPV 105

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        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 1840641109 103 ERCIACKLCEAICPAQAITIEAEERADGSRRTTRYDIDMSKCIYC------G---FCQEACPVDAIVEG----PNFEFS 168
Cdd:cd10551    83 DKCIGCRYCMAACPYGARYFNPEEPHEFGEVPVRPKGVVEKCTFCyhrldeGllpACVEACPTGARIFGdlddPNSEVS 161

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

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1840641109 105 CIACKL--CEAICPAQAITieaeeradgsRRTTRYDIDMSKCIYCGFCQEACPVDAI 159
Cdd:COG1142    52 CRHCEDapCAEVCPVGAIT----------RDDGAVVVDEEKCIGCGLCVLACPFGAI 98

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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1840641109 102 EERCIACKLCEAICPAQAITIEAEERADGSRRTTRYDIdMSKCIYCGF------CQEACPVDAI 159
Cdd:cd10554    84 EERCIGCKLCVLACPFGAIEMAPTTVPGVDWERGPRAV-AVKCDLCAGreggpaCVEACPTKAL 146

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

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1840641109 102 EERCIACKLCEAICPAQAITIEAEERADGSrrttrydidmSKCIYCGF------CQEACPVDAIV 160
Cdd:COG1142    80 EEKCIGCGLCVLACPFGAITMVGEKSRAVA----------VKCDLCGGreggpaCVEACPTGALR 134

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        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1840641109  92 EHALRRYPSG-----EERCIACKLCEAICPAQAITIEAEERadgsrrttrydiDMSKCIYCGF---------CQEACPVD 157
Cdd:cd04410    64 TGAIYKDEDGivlidEDKCIGCGSCVEACPYGAIVFDPEPG------------KAVKCDLCGDrldeglepaCVKACPTG 131

                  ...
gi 1840641109 158 AIV 160
Cdd:cd04410   132 ALT 134

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 1840641109 102 EERCIACKLCEAICPAQAITIEAEERADGSRRTtryDIDMSKCIYCGFCQEACP 155
Cdd:pfam13237   6 PDKCIGCGRCTAACPAGLTRVGAIVERLEGEAV---RIGVWKCIGCGACVEACP 56

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 1840641109 106 IACKLCEAICPAQAITIEAeeRADGSRRTTrydIDMSKCIYCGFCQEACPVDAI 159
Cdd:cd10564    86 VECRSCQDACPTQAIRFRP--RLGGIALPE---LDADACTGCGACVSVCPVGAI 134

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

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1840641109 111 CEAICPAQAITIeaeeRADGSRRttrydIDMSKCIYCGFCQEACPVDAI 159
Cdd:COG0437    68 CVKVCPTGATYK----REDGIVL-----VDYDKCIGCRYCVAACPYGAP 107

Ferredoxin [Energy production and conversion];

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1840641109 101 GEERCIACKLCEAICPAQAITIEAEERADGSRRTTRYDIDMSKCIYCGFCQEACPVDAIVEGPN 164
Cdd:COG1145   141 EAGLAILGAAAPVDALAISGGKKIEEELKIAIKKAKAVIDAEKCIGCGLCVKVCPTGAIRLKDG 204

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
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1840641109 104 RCIACKLCEAICPAQAITIEAEEraDGSR--RTTRYDIDMSKCIYCG-FCQEACPVDAI 159
Cdd:cd16373    15 LCIRCGLCVEACPTGVIQPAGLE--DGLEggRTPYLDPREGPCDLCCdACVEVCPTGAL 71

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
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1840641109 105 CIACKL--CEAICPAQAItieaEERADGSRRTTRydidmSKCIYCGFCQEACPVDAI 159
Cdd:cd16370    53 CRACEDppCAEACPTGAL----EPRKGGGVVLDK-----EKCIGCGNCVKACIVGAI 100

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

                          10        20        30
                  ....*....|....*....|....*....|....
gi 1840641109 133 RTT--RYDIDMSKCIYCGFCQEACPVDAIVEGPN 164
Cdd:COG4231    11 RTTamRYVIDEDKCTGCGACVKVCPADAIEEGDG 44

3-methyl-2-oxobutanoate dehydrogenase subunit delta;

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1840641109 102 EERCIACKLCEAICPAQAITIeaeeRADGSrrttrYDIDMSKCIYCGFCQEACPVDAI 159
Cdd:PRK09623   50 ESKCVKCYICWKFCPEPAIYI----KEDGY-----VAIDYDYCKGCGICANECPTKAI 98

Fe-S cluster domain-containing protein;

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1840641109 102 EERCIACKLCEAICPAQAIT-IEAEERADGSRRTTRYDIDMSK-----CIYCGFCQEACPVDAIV 160
Cdd:PRK07118  167 EDKCTGCGACVKACPRNVIElIPKSARVFVACNSKDKGKAVKKvcevgCIGCGKCVKACPAGAIT 231

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 1840641109 111 CEAICPAQAITIeaeeRADGsrrttRYDIDMSKCIYCGFCQEACPVDAI 159
Cdd:cd10551    61 CVKVCPTGATYK----REDG-----IVLVDYDKCIGCRYCMAACPYGAR 100

electron transport complex subunit RsxB;

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1840641109  90 RGEHALRRYPSGEERCIAcKLCEAI-CPAqaITIEAEERADGSRRTTRydIDMSKCIYCGFCQEACPVDAIVEGP 163
Cdd:PRK06991   37 AGEANYNRCPPGGAEGIA-RLAALLgKPV--IPLDPANGVERPRAVAV--IDEQLCIGCTLCMQACPVDAIVGAP 106

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

                          10        20        30
                  ....*....|....*....|....*....|....*.
gi 1840641109 139 IDMSKCIYCGFCQEACPVDAIVEGPNFEFSTETHEE 174
Cdd:COG1146     5 IDTDKCIGCGACVEVCPVDVLELDEEGKKALVINPE 40

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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1840641109  94 ALRRYPSG-----EERCIACKLCEAICPAQAITIEAEeradgsrrtTRYDIdmsKCIYCGFCQEACPVDAI 159
Cdd:cd16370    69 ALEPRKGGgvvldKEKCIGCGNCVKACIVGAIFWDEE---------TNKPI---ICIHCGYCARYCPHDVL 127

putative oxidoreductase Fe-S binding subunit; Reviewed

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1840641109 102 EERCIACKLCEAICPAQAITIEAEERADGSRRTTRYdidmsKCIYCG------FCQEACPVDAI 159
Cdd:PRK12769   84 QQKCIGCKSCVVACPFGTMQIVLTPVAAGKVKATAH-----KCDLCAgrengpACVENCPADAL 142

Pyruvate:ferredoxin oxidoreductase or related 2-oxoacid:ferredoxin oxidoreductase, delta subunit [Energy production and conversion]; Pyruvate:ferredoxin oxidoreductase or related 2-oxoacid:ferredoxin oxidoreductase, delta subunit is part of the Pathway/BioSystem: Pyruvate oxidation

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 1840641109 130 GSRRTTRYDIDMSKCIYCGFCQEACPVDAI--VEGPNFEFSTE 170
Cdd:COG1144    18 GGWRVERPVVDEDKCIGCGLCWIVCPDGAIrvDDGKYYGIDYD 60

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
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1840641109 104 RCIACK--LCEAICPAQAITIEAEERADgsrrttrydIDMSKCIYCGFCQEACPVDAI 159
Cdd:cd16374    42 RCRHCEdaPCMEVCPTGAIYRDEDGAVL---------VDPDKCIGCGMCAMACPFGVP 90

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
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1840641109 105 CIACKLCEAICPAQAITieaeeradgsrRTTR--YDIDMSKCIYCGFCQEACPVDAIV 160
Cdd:cd16372    49 CNQCGECIDVCPTGAIT-----------RDANgvVMINKKLCVGCLMCVGFCPEGAMF 95