Activating Compound | Comment | Organism | Structure |
---|---|---|---|
additional information | high concentrations of phosphate buffer are required for optimal FBEB activities in vitro, which because they promote hydrophobic protein-protein interactions between the inserted ferredoxin domain on HdrA and Fd | Methanococcus maripaludis |
Cloned (Comment) | Organism |
---|---|
recombinant expression of His-tagged enzyme complex components, Fdh, Vhu, and Hdr in Escherichia coli | Methanococcus maripaludis |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
additional information | the FBEB specific activity is slightly reduced when 1.6 M phosphate is replaced with 1.5 M phosphate buffer and 100 mM MOPS, although a similar activity is observed in 1.5 M ammonium sulfate and 100 mM MOPS. The FBEB specific activity is significantly reduced in 1.6 M MOPS | Methanococcus maripaludis |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 H2 + 2 oxidized ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB | Methanococcus maripaludis | - |
2 reduced ferredoxin [iron-sulfur] cluster + CoB + CoM + 2 H+ | - |
? | |
2 H2 + 2 oxidized ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB | Methanococcus maripaludis LL | - |
2 reduced ferredoxin [iron-sulfur] cluster + CoB + CoM + 2 H+ | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Methanococcus maripaludis | - |
and strains Mm1264 and Mm1265, derivatives of strain S2 incorporating a polyHis-tag at the C-terminus of HdrB (1264) and at the C-terminus of FdhA (1265), respectively | - |
Methanococcus maripaludis LL | - |
and strains Mm1264 and Mm1265, derivatives of strain S2 incorporating a polyHis-tag at the C-terminus of HdrB (1264) and at the C-terminus of FdhA (1265), respectively | - |
Purification (Comment) | Organism |
---|---|
recombinant His-tagged enzyme complex components, Fdh, Vhu, and Hdr from Escherichia coli by nickel affinity chromatography | Methanococcus maripaludis |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
36 | - |
FBEB activity in presence of phosphate, pH 7.0, 30°C | Methanococcus maripaludis |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 H2 + 2 oxidized ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB | - |
Methanococcus maripaludis | 2 reduced ferredoxin [iron-sulfur] cluster + CoB + CoM + 2 H+ | - |
? | |
2 H2 + 2 oxidized ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB | in Escherichia coli recombinantly expressed Clostridium pasteurianum ferredoxin is used as cosubstrate. The Vdu containing complexes show higher activity with hydrogen compared to formate. H2 oxidation by FBEB by the MvhHdr complex reduces ferredoxin (Fd) to almost 100% | Methanococcus maripaludis | 2 reduced ferredoxin [iron-sulfur] cluster + CoB + CoM + 2 H+ | - |
? | |
2 H2 + 2 oxidized ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB | - |
Methanococcus maripaludis LL | 2 reduced ferredoxin [iron-sulfur] cluster + CoB + CoM + 2 H+ | - |
? | |
2 H2 + 2 oxidized ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB | in Escherichia coli recombinantly expressed Clostridium pasteurianum ferredoxin is used as cosubstrate. The Vdu containing complexes show higher activity with hydrogen compared to formate. H2 oxidation by FBEB by the MvhHdr complex reduces ferredoxin (Fd) to almost 100% | Methanococcus maripaludis LL | 2 reduced ferredoxin [iron-sulfur] cluster + CoB + CoM + 2 H+ | - |
? | |
additional information | the non-FBEB reduction of Fd by Vhu (H2 oxidation) or Fdh (formate oxidation) is not kinetically dominant | Methanococcus maripaludis | ? | - |
- |
|
additional information | the non-FBEB reduction of Fd by Vhu (H2 oxidation) or Fdh (formate oxidation) is not kinetically dominant | Methanococcus maripaludis LL | ? | - |
- |
Subunits | Comment | Organism |
---|---|---|
More | three Hdr complexes employing two Vhu domains [(Vhu)2Hdr complex], two Fdh domains [(Fdh)2Hdr complex], or one Vhu and one Fdh domain forming a heterocomplex (Fdh/Vhu/Hdr complex) | Methanococcus maripaludis |
Synonyms | Comment | Organism |
---|---|---|
H2-driven FBEB | - |
Methanococcus maripaludis |
heterodisulfide reductase complex | - |
Methanococcus maripaludis |
hydrogenase | - |
Methanococcus maripaludis |
More | see also EC 1.8.98.6 | Methanococcus maripaludis |
Vhu | - |
Methanococcus maripaludis |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
30 | - |
assay at | Methanococcus maripaludis |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7 | - |
assay at | Methanococcus maripaludis |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
FAD | - |
Methanococcus maripaludis | |
Fe-S center | two [4Fe-4S] clusters of the inserted ferredoxin (Fd) domain | Methanococcus maripaludis | |
Ferredoxin | - |
Methanococcus maripaludis |
General Information | Comment | Organism |
---|---|---|
metabolism | heterodisulfide reductase plays a central role in the methanogenesis cycle of Methanococcus maripaludis | Methanococcus maripaludis |
metabolism | in methanogens without cytochromes, the initial endergonic reduction of CO2 to formylmethanofuran with H2-derived electrons is coupled to the exergonic reduction of a heterodisulfide of coenzymes B and M by flavin-based electron bifurcation (FBEB). Methanococcus maripaludis employs three functional heterodisulfide reductase complexes for FBEB using hydrogen and formate. In Methanococcus maripaludis, FBEB is performed by a heterodisulfide reductase (Hdr) enzyme complex that involves hydrogenase (Vhu), although formate dehydrogenase (Fdh) has been proposed as an alternative to Vhu | Methanococcus maripaludis |
additional information | when grown on formate as its sole electron donor, Methanococcus maripaludis assembles three Hdr complexes employing two Vhu domains [(Vhu)2Hdr complex], two Fdh domains [(Fdh)2Hdr complex], or one Vhu and one Fdh domain forming a heterocomplex (Fdh/Vhu/Hdr complex). Protein-protein interaction/docking analysis and modeling, usage of the crystal structure of the analogous MvhHdr complex from Methanothermococcus thermolithotrophicus (PDB ID 5ODC) as template, enzyme complex structures comparisons, overview | Methanococcus maripaludis |