Cloned (Comment) | Organism |
---|---|
genes TON_1559 to TON_1561 or frhAGB gene cluster, DNA and amino acid sequence determination and analysis, recombinant expression as Strep-tagged proteins in Escherichia coli | Thermococcus onnurineus |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Fe2+ | the alpha-subunit (FrhA) contains a binuclear [Ni-Fe] center, the beta-subunit (FrhG) contains three [4Fe-4S] clusters, while the gamma-subunit (FrhB) has one [4Fe-4S] cluster | Thermococcus onnurineus | |
Ni2+ | the alpha-subunit (FrhA) contains a binuclear [Ni-Fe] center | Thermococcus onnurineus |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
H2 + oxidized coenzyme F420 | Thermococcus onnurineus | - |
reduced coenzyme F420 | - |
? | |
H2 + thioredoxin | Thermococcus onnurineus | the frhAGB-encoded hydrogenase can transfer electrons derived from oxidation of H2 to a protein target by direct contact without the involvement of an electron carrier | reduced thioredoxin | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Thermococcus onnurineus | B6YTV8 AND B6YTV9 AND B6YTW0 | Frh subunits A, B, and C | - |
Thermococcus onnurineus | B6YTV8 AND B6YTV9 AND B6YTW0 AND | B6YTV8: alpha subunit, B6YTV9: gamma subunit, B6YTW0: beta subunit, B6YTW1: sulfur carrier protein FdhD | - |
Purification (Comment) | Organism |
---|---|
recombinant Strep-tagged enzyme subunits from Escherichia coli by affinity chromatography | Thermococcus onnurineus |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
H2 + oxidized coenzyme F420 | - |
Thermococcus onnurineus | reduced coenzyme F420 | - |
? | |
H2 + thioredoxin | the frhAGB-encoded hydrogenase can transfer electrons derived from oxidation of H2 to a protein target by direct contact without the involvement of an electron carrier | Thermococcus onnurineus | reduced thioredoxin | - |
? | |
additional information | the endogenous frhAGB-encoded hydrogenase does not exhibit F420-reducing activity | Thermococcus onnurineus | ? | - |
- |
|
oxidized methyl viologen + H2 | - |
Thermococcus onnurineus | reduced methyl viologen + H+ | - |
? |
Subunits | Comment | Organism |
---|---|---|
heterotrimer | alphabetagamma, 1 * 43000, alpha-subunit, + 1 * 30000, beta-subunit, + 1 * 25000, gamma-subunit, SDS-PAGE | Thermococcus onnurineus |
More | enzyme peptide fingerprinting using matrix-assisted laser desorption ionization-time of flight tandem mass spectrometry (MALDI-TOF MS/MS) analysis | Thermococcus onnurineus |
More | the Frh enzymes are encoded by the frhAGB genes and are heterotrimers composed of an alpha-subunit (FrhA) with a binuclear [Ni-Fe] center, a beta-subunit (FrhG) with three [4Fe-4S] clusters, and a gamma-subunit (FrhB) with one [4Fe-4S] cluster and one flavin adenine dinucleotide (FAD) as a prosthetic group | Thermococcus onnurineus |
Synonyms | Comment | Organism |
---|---|---|
F420-reducing hydrogenase | - |
Thermococcus onnurineus |
FrhABC | - |
Thermococcus onnurineus |
frhAGB-encoded hydrogenase | - |
Thermococcus onnurineus |
TON_1559 | - |
Thermococcus onnurineus |
TON_1560 | - |
Thermococcus onnurineus |
TON_1561 | - |
Thermococcus onnurineus |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
FAD | prosthetic group | Thermococcus onnurineus | |
Fe-S center | the beta-subunit (FrhG) contains three [4Fe-4S] clusters, while the gamma-subunit (FrhB) has one [4Fe-4S] cluster | Thermococcus onnurineus | |
additional information | the alpha-subunit (FrhA) contains a binuclear [Ni-Fe] center | Thermococcus onnurineus |
General Information | Comment | Organism |
---|---|---|
evolution | the F420-binding motif of the frhB-encoded subunit is not well conserved | Thermococcus onnurineus |
metabolism | electrons derived from H2 oxidation by the frhAGB-encoded hydrogenase are transferred to thioredoxin reductase (TrxR) and reduce Pdo, a redox partner of TrxR. Interaction and electron transfer are observed between TrxR and the heterodimeric hydrogenase complex (FrhAG) as well as the heterotrimeric complex (FrhAGB). Functionality of the frhAGB-encoded hydrogenase utilizing a protein as an electron acceptor | Thermococcus onnurineus |
metabolism | in general, F420-reducing hydrogenases (Frh) are key enzymes in the hydrogenotrophic methanogenesis pathway in methanogens, providing reduced F420, which serves as an electron donor in the methylene-H4MPT dehydrogenase and the methylene-H4MPT reductase reactions. Redox cascade from the frhAGB-encoded hydrogenase to Pdo via TrxR | Thermococcus onnurineus |
additional information | thioredoxin reductase (EC 1.8.1.9) TrxR might interact with the FrhA or FrhG subunit in the absence of the FrhB subunit | Thermococcus onnurineus |
physiological function | in the hyperthermophilic archaeon Thermococcus onnurineus strain NA1, the frhAGB-encoded hydrogenase, a homologue of the F420-reducing hydrogenase of methanogens, interacts with thioredoxin reductase (TrxR EC 1.8.1.9). Electrons derived from H2 oxidation by the frhAGB-encoded hydrogenase are transferred to TrxR and reduced Pdo, a redox partner of TrxR. Interaction and electron transfer are observed between TrxR and the heterodimeric hydrogenase complex (FrhAG) as well as the heterotrimeric complex (FrhAGB). Hydrogen-dependent reduction of TrxR is 7fold less efficient than when NADPH is the electron donor. TrxR can use H2 as an electron donor with the aid of the frhAGB-encoded hydrogenase as well as NAD(P)H in Thermococcus onnurineus strain NA. The frhAGB-encoded hydrogenase can transfer electrons derived from oxidation of H2 to a protein target by direct contact without the involvement of an electron carrier, which is distinct from the mechanism of its homologues, F420-reducing hydrogenases of methanogens. F420-reducing hydrogenase (Frh) is a key enzyme in the hydrogenotrophic methanogenesis pathway in methanogens, providing reduced F420, which serves as an electron donor in the methylene-H4MPT dehydrogenase and the methylene-H4MPT reductase reactions | Thermococcus onnurineus |
physiological function | key enzyme in the hydrogenotrophic methanogenesis pathway in methanogens, providing reduced F420, which serves as an electron donor in the methylene-tetrahydromethanopterin dehydrogenase and the methylene-tetrahydromethanopterin reductase reactions | Thermococcus onnurineus |