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 Fd 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 formate + 2 oxidized ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB | Methanococcus maripaludis | - |
2 CO2 + 2 reduced ferredoxin [iron-sulfur] cluster + CoB + CoM + 2 H+ | - |
? | |
2 formate + 2 oxidized ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB | Methanococcus maripaludis LL | - |
2 CO2 + 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 poly-His-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 poly-His-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 formate + 2 oxidized ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB | - |
Methanococcus maripaludis | 2 CO2 + 2 reduced ferredoxin [iron-sulfur] cluster + CoB + CoM + 2 H+ | - |
? | |
2 formate + 2 oxidized ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB | - |
Methanococcus maripaludis LL | 2 CO2 + 2 reduced ferredoxin [iron-sulfur] cluster + CoB + CoM + 2 H+ | - |
? | |
additional information | in Escherichia coli recombinantly expressed Clostridium pasteurianum ferredoxin is used as cosubstrate. The Fdh containing complexes show higher activity with formate compared to hydrogen. The non-FBEB reduction of Fd by Vhu (H2 oxidation) or Fdh (formate oxidation) is not kinetically dominant | Methanococcus maripaludis | ? | - |
- |
|
additional information | in Escherichia coli recombinantly expressed Clostridium pasteurianum ferredoxin is used as cosubstrate. The Fdh containing complexes show higher activity with formate compared to hydrogen. 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 |
---|---|---|
FDH | - |
Methanococcus maripaludis |
formate-driven FBEB | - |
Methanococcus maripaludis |
heterodisulfide reductase complex | - |
Methanococcus maripaludis |
More | see also EC 1.8.98.5 | 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. 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 |