Application | Comment | Organism |
---|---|---|
additional information | the HdrABC-MvhAGD atomic model serves as a structural template for numerous HdrABC homologs involved in diverse microbial metabolic pathways | Methanothermobacter wolfeii |
additional information | the HdrABC-MvhAGD atomic model serves as a structural template for numerous HdrABC homologs involved in diverse microbial metabolic pathways | Methanothermococcus thermolithotrophicus |
additional information | the HdrABC-MvhAGD atomic model serves as a structural template for numerous HdrABC homologs involved in diverse microbial metabolic pathways | Methanocaldococcus jannaschii |
Crystallization (Comment) | Organism |
---|---|
purified HdrABC-MvhAGD complex, X-ray diffraction structure determination and analysis at 2.15 A resolution | Methanothermococcus thermolithotrophicus |
purified HdrABC-MvhAGD complex, X-ray diffraction structure determination and analysis at 4.35 A resolution | Methanothermobacter wolfeii |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
membrane | - |
Methanothermobacter wolfeii | 16020 | - |
membrane | - |
Methanothermococcus thermolithotrophicus | 16020 | - |
membrane | - |
Methanocaldococcus jannaschii | 16020 | - |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Fe2+ | in two noncubane [4Fe-4S] clusters of HdrB. The two noncubane [4Fe-4S] clusters are composed of fused [3Fe-4S]-[2Fe-2S] units sharing 1 iron and 1 sulfur, which are coordinated at the CCG motifs | Methanothermobacter wolfeii | |
Fe2+ | in two noncubane [4Fe-4S] clusters of HdrB. The two noncubane [4Fe-4S] clusters are composed of fused [3Fe-4S]-[2Fe-2S] units sharing 1 iron and 1 sulfur, which are coordinated at the CCG motifs | Methanothermococcus thermolithotrophicus | |
Fe2+ | in two noncubane [4Fe-4S] clusters of HdrB. The two noncubane [4Fe-4S] clusters are composed of fused [3Fe-4S]-[2Fe-2S] units sharing 1 iron and 1 sulfur, which are coordinated at the CCG motifs | Methanocaldococcus jannaschii |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | Methanothermobacter wolfeii | - |
2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM | - |
? | |
2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | Methanothermococcus thermolithotrophicus | - |
2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM | - |
? | |
2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | Methanocaldococcus jannaschii | - |
2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM | - |
? | |
2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | Methanocaldococcus jannaschii NBRC 100440 | - |
2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM | - |
? | |
2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | Methanocaldococcus jannaschii DSM 2661 | - |
2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM | - |
? | |
2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | Methanocaldococcus jannaschii ATCC 43067 | - |
2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM | - |
? | |
2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | Methanocaldococcus jannaschii JAL-1 | - |
2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM | - |
? | |
2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | Methanothermococcus thermolithotrophicus DSM 2095 | - |
2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM | - |
? | |
2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | Methanocaldococcus jannaschii JCM 10045 | - |
2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Methanocaldococcus jannaschii | P60200 AND Q58153 AND Q58273 AND Q58154 AND Q58274 | CoB-CoM heterodisulfide reductase subunits A, B1, B2, C1, and C2; Methanococcus jannaschii | - |
Methanocaldococcus jannaschii ATCC 43067 | P60200 AND Q58153 AND Q58273 AND Q58154 AND Q58274 | CoB-CoM heterodisulfide reductase subunits A, B1, B2, C1, and C2; Methanococcus jannaschii | - |
Methanocaldococcus jannaschii DSM 2661 | P60200 AND Q58153 AND Q58273 AND Q58154 AND Q58274 | CoB-CoM heterodisulfide reductase subunits A, B1, B2, C1, and C2; Methanococcus jannaschii | - |
Methanocaldococcus jannaschii JAL-1 | P60200 AND Q58153 AND Q58273 AND Q58154 AND Q58274 | CoB-CoM heterodisulfide reductase subunits A, B1, B2, C1, and C2; Methanococcus jannaschii | - |
Methanocaldococcus jannaschii JCM 10045 | P60200 AND Q58153 AND Q58273 AND Q58154 AND Q58274 | CoB-CoM heterodisulfide reductase subunits A, B1, B2, C1, and C2; Methanococcus jannaschii | - |
Methanocaldococcus jannaschii NBRC 100440 | P60200 AND Q58153 AND Q58273 AND Q58154 AND Q58274 | CoB-CoM heterodisulfide reductase subunits A, B1, B2, C1, and C2; Methanococcus jannaschii | - |
Methanothermobacter wolfeii | - |
- |
- |
Methanothermococcus thermolithotrophicus | A0A2D0TCB9 AND A0A2D0TCB4 AND A0A2D0TC97 | CoB-CoM heterodisulfide reductase subunits A, B, and C | - |
Methanothermococcus thermolithotrophicus DSM 2095 | A0A2D0TCB9 AND A0A2D0TCB4 AND A0A2D0TC97 | CoB-CoM heterodisulfide reductase subunits A, B, and C | - |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM = 2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | subunit HdrB of heterodisulfide reductase (HdrABC-MvhAGD) contains two noncubane [4Fe-4S] clusters tht are involved in reduction activity. The heterodisulfide is clamped between the two noncubane [4Fe-4S] clusters and homolytically cleaved, forming coenzyme M and B bound to each iron. Coenzymes are consecutively released upon one-by-one electron transfer | Methanothermobacter wolfeii | |
2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM = 2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | subunit HdrB of heterodisulfide reductase (HdrABC-MvhAGD) contains two noncubane [4Fe-4S] clusters tht are involved in reduction activity. The heterodisulfide is clamped between the two noncubane [4Fe-4S] clusters and homolytically cleaved, forming coenzyme M and B bound to each iron. Coenzymes are consecutively released upon one-by-one electron transfer | Methanothermococcus thermolithotrophicus | |
2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM = 2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | subunit HdrB of heterodisulfide reductase (HdrABC-MvhAGD) contains two noncubane [4Fe-4S] clusters tht are involved in reduction activity. The heterodisulfide is clamped between the two noncubane [4Fe-4S] clusters and homolytically cleaved, forming coenzyme M and B bound to each iron. Coenzymes are consecutively released upon one-by-one electron transfer | Methanocaldococcus jannaschii |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | - |
Methanothermobacter wolfeii | 2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM | - |
? | |
2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | - |
Methanothermococcus thermolithotrophicus | 2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM | - |
? | |
2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | - |
Methanocaldococcus jannaschii | 2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM | - |
? | |
2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | - |
Methanocaldococcus jannaschii NBRC 100440 | 2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM | - |
? | |
2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | - |
Methanocaldococcus jannaschii DSM 2661 | 2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM | - |
? | |
2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | - |
Methanocaldococcus jannaschii ATCC 43067 | 2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM | - |
? | |
2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | - |
Methanocaldococcus jannaschii JAL-1 | 2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM | - |
? | |
2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | - |
Methanothermococcus thermolithotrophicus DSM 2095 | 2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM | - |
? | |
2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | - |
Methanocaldococcus jannaschii JCM 10045 | 2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM | - |
? |
Subunits | Comment | Organism |
---|---|---|
oligomer | structure analysis of the native heterododecameric HdrABC-MvhAGD complex, overview. The multisubunit enzyme complex is composed of a dimer of two HdrABC-MvhAGD heterohexamers with a flavin-containing HdrA dimer in the center, to which two catalytic arms, MvhAGD and HdrBC, are attached | Methanocaldococcus jannaschii |
oligomer | structure analysis of the native heterododecameric HdrABC-MvhAGD complex, overview. The multisubunit enzyme complex is composed of a dimer of two HdrABC-MvhAGD heterohexamers with a flavin-containing HdrA dimer in the center, to which two catalytic arms, MvhAGD and HdrBC, are attached. HdrA is tightly associated with HdrA' (amino acid residues of the partner protomer are marked with an apostrophe) and comprises anN-terminal (1 to 133), a thioredoxin-reductase (145 to 236 and 315 to 567), an inserted ferredoxin (237 to 314), and a C-terminal ferredoxin domain (568 to 654) | Methanothermococcus thermolithotrophicus |
oligomer | the multisubunit enzyme complex is composed of a dimer of two HdrABC-MvhAGD heterohexamers with a flavin-containing HdrA dimer in the center, to which two catalytic arms, MvhAGD and HdrBC, are attached | Methanothermobacter wolfeii |
Synonyms | Comment | Organism |
---|---|---|
HdrABC | - |
Methanothermobacter wolfeii |
HdrABC | - |
Methanothermococcus thermolithotrophicus |
HdrABC | - |
Methanocaldococcus jannaschii |
heterodisulfide reductase | - |
Methanothermobacter wolfeii |
heterodisulfide reductase | - |
Methanothermococcus thermolithotrophicus |
heterodisulfide reductase | - |
Methanocaldococcus jannaschii |
More | cf. EC 1.8.98.1, EC 1.8.98.4, and EC 1.8.98.5 | Methanothermobacter wolfeii |
More | cf. EC 1.8.98.1, EC 1.8.98.4, and EC 1.8.98.5 | Methanothermococcus thermolithotrophicus |
More | cf. EC 1.8.98.1, EC 1.8.98.4, and EC 1.8.98.5 | Methanocaldococcus jannaschii |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
FAD | the multisubunit enzyme complex is composed of a dimer of two HdrABC-MvhAGD heterohexamers with a flavin-containing HdrA dimer in the center, to which two catalytic arms, MvhAGD and HdrBC, are attached | Methanothermobacter wolfeii | |
FAD | the multisubunit enzyme complex is composed of a dimer of two HdrABC-MvhAGD heterohexamers with a flavin-containing HdrA dimer in the center, to which two catalytic arms, MvhAGD and HdrBC, are attached | Methanothermococcus thermolithotrophicus | |
FAD | the multisubunit enzyme complex is composed of a dimer of two HdrABC-MvhAGD heterohexamers with a flavin-containing HdrA dimer in the center, to which two catalytic arms, MvhAGD and HdrBC, are attached | Methanocaldococcus jannaschii | |
Fe-S center | subunits HdrB of heterodisulfide reductase (HdrABC-MvhAGD) contains two noncubane [4Fe-4S] clusters used for reduction activity. The two noncubane [4Fe-4S] clusters are composed of fused [3Fe-4S]-[2Fe-2S] units sharing 1 iron (Fe) and 1 sulfur (S), which are coordinated at the CCG motifs. The N-terminal domain has a fold similar to MvhD but contains, instead of a [2Fe-2S] cluster, a [4Fe-4S] cluster (HA3) that is unusually ligated by five cysteines | Methanothermobacter wolfeii | |
Fe-S center | subunits HdrB of heterodisulfide reductase (HdrABC-MvhAGD) contains two noncubane [4Fe-4S] clusters used for reduction activity. The two noncubane [4Fe-4S] clusters are composed of fused [3Fe-4S]-[2Fe-2S] units sharing 1 iron (Fe) and 1 sulfur (S), which are coordinated at the CCG motifs. The N-terminal domain has a fold similar to MvhD but contains, instead of a [2Fe-2S] cluster, a [4Fe-4S] cluster (HA3) that is unusually ligated by five cysteines | Methanothermococcus thermolithotrophicus | |
Fe-S center | subunits HdrB of heterodisulfide reductase (HdrABC-MvhAGD) contains two noncubane [4Fe-4S] clusters used for reduction activity. The two noncubane [4Fe-4S] clusters are composed of fused [3Fe-4S]-[2Fe-2S] units sharing 1 iron and 1 sulfur, which are coordinated at the CCG motifs. The N-terminal domain has a fold similar to MvhD but contains, instead of a [2Fe-2S] cluster, a [4Fe-4S] cluster (HA3) that is unusually ligated by five cysteines | Methanocaldococcus jannaschii | |
additional information | the thioredoxin reductase domain of HdrA (145 to 236 and 315 to 567) resembles thioredoxin reductase in the fold and geometry of the FAD-binding site but forms a completely different dimer interface, owing to the perpendicular position of the respective two-fold axes. The thioredoxin-reductase domain of HdrA has, in addition, a [4Fe-4S] cluster (HA4) that is surrounded by several basic residues and coordinated with a Cys386, Cys399, Cys403, and Cys404 sequence motif (consensus sequence CX10-16-Y/W/H/F-C-S/A/C-X2-3CC) | Methanothermobacter wolfeii | |
additional information | the thioredoxin reductase domain of HdrA (145 to 236 and 315 to 567) resembles thioredoxin reductase in the fold and geometry of the FAD-binding site but forms a completely different dimer interface, owing to the perpendicular position of the respective two-fold axes. The thioredoxin-reductase domain of HdrA has, in addition, a [4Fe-4S] cluster (HA4) that is surrounded by several basic residues and coordinated with a Cys386, Cys399, Cys403, and Cys404 sequence motif (consensus sequence CX10-16-Y/W/H/F-C-S/A/C-X2-3CC) | Methanothermococcus thermolithotrophicus | |
additional information | the thioredoxin reductase domain of HdrA (145 to 236 and 315 to 567) resembles thioredoxin reductase in the fold and geometry of the FAD-binding site but forms a completely different dimer interface, owing to the perpendicular position of the respective two-fold axes. The thioredoxin-reductase domain of HdrA has, in addition, a [4Fe-4S] cluster (HA4) that is surrounded by several basic residues and coordinated with a Cys386, Cys399, Cys403, and Cys404 sequence motif (consensus sequence CX10-16-Y/W/H/F-C-S/A/C-X2-3CC) | Methanocaldococcus jannaschii |
General Information | Comment | Organism |
---|---|---|
evolution | HdrA homologues are found in many other microorganisms, i.e. anaerobic methanotrophic archaea, sulfate-reducing bacteria and archaea, sulfur-oxidizing bacteria, acetogenic bacteria, knallgas bacteria, and metal-reducing bacteria | Methanothermobacter wolfeii |
evolution | HdrA homologues are found in many other microorganisms, i.e. anaerobic methanotrophic archaea, sulfate-reducing bacteria and archaea, sulfur-oxidizing bacteria, acetogenic bacteria, knallgas bacteria, and metal-reducing bacteria. The fifth cysteine Cys197' of Methanothermococcus thermolithotrophicus HdrA is exchanged for a selenocysteine in HdrA from Methanocaldococcus jannaschii | Methanothermococcus thermolithotrophicus |
evolution | HdrA homologues are found in many other microorganisms, i.e. anaerobic methanotrophic archaea, sulfate-reducing bacteria and archaea, sulfur-oxidizing bacteria, acetogenic bacteria, knallgas bacteria, and metal-reducing bacteria. The fifth cysteine Cys197' of Methanothermococcus thermolithotrophicus HdrA is exchanged for a selenocysteine in HdrA from Methanocaldococcus jannaschii | Methanocaldococcus jannaschii |
metabolism | in methanogenic archaea, the carbon dioxide (CO2) fixation and methane-forming steps are linked through the heterodisulfide reductase (HdrABC)-[NiFe]-hydrogenase (MvhAGD) complex that uses flavin-based electron bifurcation to reduce ferredoxin and the heterodisulfide of coenzymes M and B | Methanothermobacter wolfeii |
metabolism | in methanogenic archaea, the carbon dioxide (CO2) fixation and methane-forming steps are linked through the heterodisulfide reductase (HdrABC)-[NiFe]-hydrogenase (MvhAGD) complex that uses flavin-based electron bifurcation to reduce ferredoxin and the heterodisulfide of coenzymes M and B | Methanothermococcus thermolithotrophicus |
metabolism | in methanogenic archaea, the carbon dioxide (CO2) fixation and methane-forming steps are linked through the heterodisulfide reductase (HdrABC)-[NiFe]-hydrogenase (MvhAGD) complex that uses flavin-based electron bifurcation to reduce ferredoxin and the heterodisulfide of coenzymes M and B | Methanocaldococcus jannaschii |
additional information | the methanogenic heterodisulfide reductase (HdrABC-MvhAGD) uses two noncubane [4Fe-4S] clusters for reduction. Analysis of the structure of the native heterododecameric HdrABC-MvhAGD complex at 2.15 A resolution. Subunit HdrB of heterodisulfide reductase (HdrABC-MvhAGD) contains two noncubane [4Fe-4S] clusters tht are involved in reduction activity. The heterodisulfide is clamped between the two noncubane [4Fe-4S] clusters and homolytically cleaved, forming coenzyme M and B bound to each iron. Coenzymes are consecutively released upon one-by-one electron transfer. The HdrABC-MvhAGD atomic model serves as a structural template for numerous HdrABC homologs involved in diverse microbial metabolic pathways. The multisubunit enzyme complex is composed of a dimer of two HdrABC-MvhAGD heterohexamers with a flavin-containing HdrA dimer in the center, to which two catalytic arms, MvhAGD and HdrBC, are attached. MvhA and MvhG are homologous to the large and small subunits of [NiFe] hydrogenase (EC 1.12.7.2), respectively. The thioredoxin reductase domain of HdrA (145 to 236 and 315 to 567) resembles thioredoxin reductase in the fold and geometry of the FAD-binding site but forms a completely different dimer interface, owing to the perpendicular position of the respective two-fold axes. The thioredoxin-reductase domain of HdrA has, in addition, a [4Fe-4S] cluster (HA4) that is surrounded by several basic residues and coordinated with a Cys386, Cys399, Cys403, and Cys404 sequence motif (consensus sequence CX10-16-Y/W/H/F-C-S/A/C-X2-3CC). HdrB is unusual in that spectroscopic studies have suggested that disulfide reduction occurs through two one-electron steps rather than the typical two-electron step. HdrB contains a duplicated CCG motif with the sequence CX31-39CCX35-36CXXC. This motif is predicted to be a binding motif for iron-sulfur clusters, which occurs in numerous microbes. Structure comparisons | Methanothermobacter wolfeii |
additional information | the methanogenic heterodisulfide reductase (HdrABC-MvhAGD) uses two noncubane [4Fe-4S] clusters for reduction. Analysis of the structure of the native heterododecameric HdrABC-MvhAGD complex at 2.15 A resolution. Subunit HdrB of heterodisulfide reductase (HdrABC-MvhAGD) contains two noncubane [4Fe-4S] clusters tht are involved in reduction activity. The heterodisulfide is clamped between the two noncubane [4Fe-4S] clusters and homolytically cleaved, forming coenzyme M and B bound to each iron. Coenzymes are consecutively released upon one-by-one electron transfer. The HdrABC-MvhAGD atomic model serves as a structural template for numerous HdrABC homologs involved in diverse microbial metabolic pathways. The multisubunit enzyme complex is composed of a dimer of two HdrABC-MvhAGD heterohexamers with a flavin-containing HdrA dimer in the center, to which two catalytic arms, MvhAGD and HdrBC, are attached. MvhA and MvhG are homologous to the large and small subunits of [NiFe] hydrogenase (EC 1.12.7.2), respectively. The thioredoxin reductase domain of HdrA (145 to 236 and 315 to 567) resembles thioredoxin reductase in the fold and geometry of the FAD-binding site but forms a completely different dimer interface, owing to the perpendicular position of the respective two-fold axes. The thioredoxin-reductase domain of HdrA has, in addition, a [4Fe-4S] cluster (HA4) that is surrounded by several basic residues and coordinated with a Cys386, Cys399, Cys403, and Cys404 sequence motif (consensus sequence CX10-16-Y/W/H/F-C-S/A/C-X2-3CC). HdrB is unusual in that spectroscopic studies have suggested that disulfide reduction occurs through two one-electron steps rather than the typical two-electron step. HdrB contains a duplicated CCG motif with the sequence CX31-39CCX35-36CXXC. This motif is predicted to be a binding motif for iron-sulfur clusters, which occurs in numerous microbes. Structure comparisons | Methanocaldococcus jannaschii |
additional information | the methanogenic heterodisulfide reductase (HdrABC-MvhAGD) uses two noncubane [4Fe-4S] clusters for reduction. Analysis of the structure of the native heterododecameric HdrABC-MvhAGD complex at 2.15 A resolution. Subunit HdrB of heterodisulfide reductase (HdrABC-MvhAGD) contains two noncubane [4Fe-4S] clusters tht are involved in reduction activity. The heterodisulfide is clamped between the two noncubane [4Fe-4S] clusters and homolytically cleaved, forming coenzyme M and B bound to each iron. Coenzymes are consecutively released upon one-by-one electron transfer. The HdrABC-MvhAGD atomic model serves as a structural template for numerous HdrABC homologs involved in diverse microbial metabolic pathways. The multisubunit enzyme complex is composed of a dimer of two HdrABC-MvhAGD heterohexamers with a flavin-containing HdrA dimer in the center, to which two catalytic arms, MvhAGD and HdrBC, are attached. MvhA and MvhG are homologous to the large and small subunits of [NiFe] hydrogenase (EC 1.12.7.2), respectively. The thioredoxin reductase domain of HdrA (145 to 236 and 315 to 567) resembles thioredoxin reductase in the fold and geometry of the FAD-binding site but forms a completely different dimer interface, owing to the perpendicular position of the respective two-fold axes. The thioredoxin-reductase domain of HdrA has, in addition, a [4Fe-4S] cluster (HA4) that is surrounded by several basic residues and coordinated with a Cys386, Cys399, Cys403, and Cys404 sequence motif (consensus sequence CX10-16-Y/W/H/F-C-S/A/C-X2-3CC). HdrB is unusual in that spectroscopic studies have suggested that disulfide reduction occurs through two one-electron steps rather than the typical two-electron step. HdrB contains a duplicated CCG motif with the sequence CX31-39CCX35-36CXXC. This motif is predicted to be a binding motif for iron-sulfur clusters, which occurs in numerous microbes. Structure comparisons. Structure-function anaysis, detailed overview | Methanothermococcus thermolithotrophicus |
physiological function | the HdrABC-MvhAGD complex catalyzes an iron-sulfur cluster-assisted disulfide reduction reaction. This reaction is integrated into a flavin-based electron bifurcation (FBEB) process, a mode of energy coupling that optimizes the energy yield of the cell. The key subunits are HdrA, which carries the electron-bifurcating flavin adenine dinucleotide (FAD), and HdrB, which has been proposed to be the heterodisulfide reductase site | Methanothermobacter wolfeii |
physiological function | the HdrABC-MvhAGD complex catalyzes an iron-sulfur cluster-assisted disulfide reduction reaction. This reaction is integrated into a flavin-based electron bifurcation (FBEB) process, a mode of energy coupling that optimizes the energy yield of the cell. The key subunits are HdrA, which carries the electron-bifurcating flavin adenine dinucleotide (FAD), and HdrB, which has been proposed to be the heterodisulfide reductase site | Methanothermococcus thermolithotrophicus |
physiological function | the HdrABC-MvhAGD complex catalyzes an iron-sulfur cluster-assisted disulfide reduction reaction. This reaction is integrated into a flavin-based electron bifurcation (FBEB) process, a mode of energy coupling that optimizes the energy yield of the cell. The key subunits are HdrA, which carries the electron-bifurcating flavin adenine dinucleotide (FAD), and HdrB, which has been proposed to be the heterodisulfide reductase site | Methanocaldococcus jannaschii |