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Your query returned 8 entries. Printable version
EC | 1.3.4.1 | ||||||||||||
Accepted name: | fumarate reductase (CoM/CoB) | ||||||||||||
Reaction: | fumarate + CoM + CoB = succinate + CoM-S-S-CoB | ||||||||||||
Glossary: | CoB = coenzyme B = N-(7-sulfanylheptanoyl)threonine = N-(7-mercaptoheptanoyl)threonine (deprecated) CoM = coenzyme M = 2-sulfanylethane-1-sulfonate = 2-mercaptoethanesulfonate (deprecated) |
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Other name(s): | thiol:fumarate reductase; Tfr | ||||||||||||
Systematic name: | fumarate CoM:CoB oxidoreductase (succinate-forming) | ||||||||||||
Comments: | The enzyme, isolated from the archaeon Methanobacterium thermoautotrophicum, is very oxygen sensitive. It cannot use reduced flavins, reduced coenzyme F420, or NAD(P)H as an electron donor. Distinct from EC 1.3.1.6 [fumarate reductase (NADH)], EC 1.3.5.1 [succinate dehydrogenase (ubiquinone)], and EC 1.3.5.4 [fumarate reductase (quinol)]. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc | ||||||||||||
References: |
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EC | 1.3.98.2 | ||||||||||||
Transferred entry: | fumarate reductase (CoM/CoB). Now EC 1.3.4.1, fumarate reductase (CoM/CoB) | ||||||||||||
EC | 1.8.7.3 | ||||||||||||
Accepted name: | ferredoxin:CoB-CoM heterodisulfide reductase | ||||||||||||
Reaction: | 2 oxidized ferredoxin [iron-sulfur] cluster + CoB + CoM = 2 reduced ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB + 2 H+ | ||||||||||||
Glossary: | CoB = coenzyme B = N-(7-sulfanylheptanoyl)threonine = N-(7-mercaptoheptanoyl)threonine 3-O-phosphate (deprecated) CoM = coenzyme M = 2-sulfanylethane-1-sulfonate = 2-mercaptoethanesulfonate (deprecated) CoM-S-S-CoB = CoB-CoM heterodisulfide = N-{7-[(2-sulfoethyl)dithio]heptanoyl}-O3-phospho-L-threonine = O3-phospho-N-{7-[2-(2-sulfoethyl)disulfan-1-yl]heptanoyl}-L-threonine |
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Other name(s): | hdrABC (gene names); hdrA1B1C1 (gene names); hdrA2B2C2 (gene names) | ||||||||||||
Systematic name: | CoB,CoM:ferredoxin oxidoreductase | ||||||||||||
Comments: | HdrABC is an enzyme complex that is found in most methanogens and catalyses the reduction of the CoB-CoM heterodisulfide back to CoB and CoM. HdrA contains a FAD cofactor that acts as the entry point for electrons, which are transferred via HdrC to the HdrB catalytic subunit. One form of the enzyme from Methanosarcina acetivorans (HdrA2B2C2) can also catalyse EC 1.8.98.4, coenzyme F420:CoB-CoM heterodisulfide,ferredoxin reductase. cf. EC 1.8.98.5, H2:CoB-CoM heterodisulfide,ferredoxin reductase, EC 1.8.98.6, formate:CoB-CoM heterodisulfide,ferredoxin reductase, and EC 1.8.98.1, dihydromethanophenazine:CoB-CoM heterodisulfide reductase. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc | ||||||||||||
References: |
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EC | 1.8.98.1 | ||||||||||||
Accepted name: | dihydromethanophenazine:CoB-CoM heterodisulfide reductase | ||||||||||||
Reaction: | CoB + CoM + methanophenazine = CoM-S-S-CoB + dihydromethanophenazine | ||||||||||||
For diagram of methane biosynthesis, click here | |||||||||||||
Glossary: | CoB = coenzyme B = N-(7-sulfanylheptanoyl)threonine = N-(7-mercaptoheptanoyl)threonine 3-O-phosphate (deprecated) CoM = coenzyme M = 2-sulfanylethane-1-sulfonate = 2-mercaptoethanesulfonate (deprecated) methanophenazine = 2-{[(6E,10E,14E)-3,7,11,15,19-pentamethylicosa-6,10,14,18-tetraen-1-yl]oxy}phenazine CoM-S-S-CoB = CoB-CoM heterodisulfide = N-{7-[(2-sulfoethyl)dithio]heptanoyl}-O3-phospho-L-threonine = O3-phospho-N-{7-[2-(2-sulfoethyl)disulfan-1-yl]heptanoyl}-L-threonine |
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Other name(s): | hdrDE (gene names); CoB—CoM heterodisulfide reductase (ambiguous); heterodisulfide reductase (ambiguous); coenzyme B:coenzyme M:methanophenazine oxidoreductase | ||||||||||||
Systematic name: | CoB:CoM:methanophenazine oxidoreductase | ||||||||||||
Comments: | This enzyme, found in methanogenic archaea that belong to the Methanosarcinales order, regenerates CoM and CoB after the action of EC 2.8.4.1, coenzyme-B sulfoethylthiotransferase. It is a membrane-bound enzyme that contains (per heterodimeric unit) two distinct b-type hemes and two [4Fe-4S] clusters. cf. EC 1.8.7.3, ferredoxin:CoB-CoM heterodisulfide reductase, EC 1.8.98.5, H2:CoB-CoM heterodisulfide,ferredoxin reductase, EC 1.8.98.6, formate:CoB-CoM heterodisulfide,ferredoxin reductase and EC 1.8.98.4, coenzyme F420:CoB-CoM heterodisulfide,ferredoxin reductase. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, PDB | ||||||||||||
References: |
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EC | 1.8.98.4 | ||||||||||||
Accepted name: | coenzyme F420:CoB-CoM heterodisulfide,ferredoxin reductase | ||||||||||||
Reaction: | 2 oxidized coenzyme F420 + 2 reduced ferredoxin [iron-sulfur] cluster + CoB + CoM + 2 H+ = 2 reduced coenzyme F420 + 2 oxidized ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB | ||||||||||||
Glossary: | CoB = coenzyme B = N-(7-sulfanylheptanoyl)threonine = N-(7-mercaptoheptanoyl)threonine 3-O-phosphate (deprecated) CoM = coenzyme M = 2-sulfanylethane-1-sulfonate = 2-mercaptoethanesulfonate (deprecated) CoM-S-S-CoB = CoB-CoM heterodisulfide = N-{7-[(2-sulfoethyl)dithio]heptanoyl}-O3-phospho-L-threonine = O3-phospho-N-{7-[2-(2-sulfoethyl)disulfan-1-yl]heptanoyl}-L-threonine |
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Other name(s): | hdrA2B2C2 (gene names) | ||||||||||||
Systematic name: | CoB,CoM,ferredoxin:coenzyme F420 oxidoreductase | ||||||||||||
Comments: | The enzyme, characterized from the archaeon Methanosarcina acetivorans, catalyses the reduction of CoB-CoM heterodisulfide back to CoB and CoM. The enzyme consists of three components, HdrA, HdrB and HdrC, all of which contain [4Fe-4S] clusters. Electrons enter at HdrA, which also contains FAD, and are transferred via HdrC to the catalytic component, HdrB. During methanogenesis from acetate the enzyme catalyses the activity of EC 1.8.7.3, ferredoxin:CoB-CoM heterodisulfide reductase. However, it can also use electron bifurcation to direct electron pairs from reduced coenzyme F420 towards the reduction of both ferredoxin and CoB-CoM heterodisulfide. This activity is proposed to take place during Fe(III)-dependent anaerobic methane oxidation. cf. EC 1.8.98.5, H2:CoB-CoM heterodisulfide,ferredoxin reductase, EC 1.8.98.6, formate:CoB-CoM heterodisulfide,ferredoxin reductase, and EC 1.8.98.1, dihydromethanophenazine:CoB-CoM heterodisulfide reductase. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc | ||||||||||||
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EC | 1.8.98.5 | ||||||||||||
Accepted name: | H2:CoB-CoM heterodisulfide,ferredoxin reductase | ||||||||||||
Reaction: | 2 reduced ferredoxin [iron-sulfur] cluster + CoB + CoM + 2 H+ = 2 H2 + 2 oxidized ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB | ||||||||||||
Glossary: | CoB = coenzyme B = N-(7-sulfanylheptanoyl)threonine = N-(7-mercaptoheptanoyl)threonine 3-O-phosphate (deprecated) CoM = coenzyme M = 2-sulfanylethane-1-sulfonate = 2-mercaptoethanesulfonate (deprecated) CoM-S-S-CoB = CoB-CoM heterodisulfide = N-{7-[(2-sulfoethyl)dithio]heptanoyl}-O3-phospho-L-threonine = O3-phospho-N-{7-[2-(2-sulfoethyl)disulfan-1-yl]heptanoyl}-L-threonine |
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Systematic name: | CoB,CoM,ferredoxin:H2 oxidoreductase | ||||||||||||
Comments: | This enzyme complex is found in H2-oxidizing CO2-reducing methanogenic archaea such as Methanothermobacter thermautotrophicus. It consists of a cytoplasmic complex of HdrABC reductase and MvhAGD hydrogenase. Electron pairs donated by the hydrogenase are transferred via its δ subunit to the HdrA subunit of the reductase, where they are bifurcated, reducing both ferredoxin and CoB-CoM heterodisulfide. The reductase can also form a similar complex with formate dehydrogenase, see EC 1.8.98.6, formate:CoB-CoM heterodisulfide,ferredoxin reductase. cf. EC 1.8.7.3, ferredoxin:CoB-CoM heterodisulfide reductase, EC 1.8.98.4, coenzyme F420:CoB-CoM heterodisulfide,ferredoxin reductase, and EC 1.8.98.1, dihydromethanophenazine:CoB-CoM heterodisulfide reductase. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc | ||||||||||||
References: |
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EC | 1.8.98.6 | ||||||||||||
Accepted name: | formate:CoB-CoM heterodisulfide,ferredoxin reductase | ||||||||||||
Reaction: | 2 CO2 + 2 reduced ferredoxin [iron-sulfur] cluster + CoB + CoM + 2 H+ = 2 formate + 2 oxidized ferredoxin [iron-sulfur] cluster + CoM-S-S-CoB | ||||||||||||
Glossary: | CoB = coenzyme B = N-(7-sulfanylheptanoyl)threonine = N-(7-mercaptoheptanoyl)threonine 3-O-phosphate (deprecated) CoM = coenzyme M = 2-sulfanylethane-1-sulfonate = 2-mercaptoethanesulfonate (deprecated) CoM-S-S-CoB = CoB-CoM heterodisulfide = N-{7-[(2-sulfoethyl)dithio]heptanoyl}-O3-phospho-L-threonine = O3-phospho-N-{7-[2-(2-sulfoethyl)disulfan-1-yl]heptanoyl}-L-threonine |
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Systematic name: | coenzyme B,coenzyme M,ferredoxin:formate oxidoreductase | ||||||||||||
Comments: | The enzyme is found in formate-oxidizing CO2-reducing methanogenic archaea such as Methanococcus maripaludis. It consists of a cytoplasmic complex of HdrABC reductase and formate dehydrogenase. Electron pairs donated by formate dehydrogenase are transferred to the HdrA subunit of the reductase, where they are bifurcated, reducing both ferredoxin and CoB-CoM heterodisulfide. cf. EC 1.8.7.3, ferredoxin:CoB-CoM heterodisulfide reductase, EC 1.8.98.4, coenzyme F420:CoB-CoM heterodisulfide,ferredoxin reductase, EC 1.8.98.5, H2:CoB-CoM heterodisulfide,ferredoxin reductase, and EC 1.8.98.1, dihydromethanophenazine:CoB-CoM heterodisulfide reductase. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc | ||||||||||||
References: |
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EC | 2.8.4.1 | ||||||||||||
Accepted name: | coenzyme-B sulfoethylthiotransferase | ||||||||||||
Reaction: | methyl-CoM + CoB = CoM-S-S-CoB + methane | ||||||||||||
For diagram of methane biosynthesis, click here | |||||||||||||
Glossary: | CoB = coenzyme B = N-(7-sulfanylheptanoyl)threonine = N-(7-mercaptoheptanoyl)threonine 3-O-phosphate (deprecated) CoM = coenzyme M = 2-sulfanylethane-1-sulfonate = 2-mercaptoethanesulfonate (deprecated) |
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Other name(s): | methyl-CoM reductase; methyl coenzyme M reductase | ||||||||||||
Systematic name: | methyl-CoM:CoB S-(2-sulfoethyl)thiotransferase | ||||||||||||
Comments: | This enzyme catalyses the final step in methanogenesis, the biological production of methane. This important anaerobic process is carried out only by methanogenic archaea. The enzyme can also function in reverse, for anaerobic oxidation of methane.The enzyme requires the hydroporphinoid nickel complex coenzyme F430. Highly specific for coenzyme B with a heptanoyl chain; ethyl CoM and difluoromethyl CoM are poor substrates. The sulfide sulfur can be replaced by selenium but not by oxygen. | ||||||||||||
Links to other databases: | BRENDA, EAWAG-BBD, EXPASY, KEGG, MetaCyc, PDB | ||||||||||||
References: |
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