EC |
1.3.1.85 |
Accepted name: |
crotonyl-CoA carboxylase/reductase |
Reaction: |
(2S)-ethylmalonyl-CoA + NADP+ = (E)-but-2-enoyl-CoA + CO2 + NADPH + H+ |
Glossary: |
(E)-but-2-enoyl-CoA = crotonyl-CoA |
Other name(s): |
CCR; crotonyl-CoA reductase (carboxylating) |
Systematic name: |
(2S)-ethylmalonyl-CoA:NADP+ oxidoreductase (decarboxylating) |
Comments: |
The reaction is catalysed in the reverse direction. This enzyme, isolated from the bacterium Rhodobacter sphaeroides, catalyses (E)-but-2-enoyl-CoA-dependent oxidation of NADPH in the presence of CO2. When CO2 is absent, the enzyme catalyses the reduction of (E)-but-2-enoyl-CoA to butanoyl-CoA, but with only 10% of maximal activity (relative to (E)-but-2-enoyl-CoA carboxylation). |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc |
References: |
1. |
Erb, T.J., Berg, I.A., Brecht, V., Muller, M., Fuchs, G. and Alber, B.E. Synthesis of C5-dicarboxylic acids from C2-units involving crotonyl-CoA carboxylase/reductase: the ethylmalonyl-CoA pathway. Proc. Natl. Acad. Sci. USA 104 (2007) 10631–10636. [DOI] [PMID: 17548827] |
2. |
Erb, T.J., Brecht, V., Fuchs, G., Muller, M. and Alber, B.E. Carboxylation mechanism and stereochemistry of crotonyl-CoA carboxylase/reductase, a carboxylating enoyl-thioester reductase. Proc. Natl. Acad. Sci. USA 106 (2009) 8871–8876. [DOI] [PMID: 19458256] |
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[EC 1.3.1.85 created 2011] |
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EC |
1.3.1.86 |
Accepted name: |
crotonyl-CoA reductase |
Reaction: |
butanoyl-CoA + NADP+ = (E)-but-2-enoyl-CoA + NADPH + H+ |
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For diagram of lysine catabolism, click here |
Glossary: |
(E)-but-2-enoyl-CoA = crotonyl-CoA
butanoyl-CoA = butyryl-CoA |
Other name(s): |
butyryl-CoA dehydrogenase; butyryl dehydrogenase; unsaturated acyl-CoA reductase; ethylene reductase; enoyl-coenzyme A reductase; unsaturated acyl coenzyme A reductase; butyryl coenzyme A dehydrogenase; short-chain acyl CoA dehydrogenase; short-chain acyl-coenzyme A dehydrogenase; 3-hydroxyacyl CoA reductase; butanoyl-CoA:(acceptor) 2,3-oxidoreductase; CCR |
Systematic name: |
butanoyl-CoA:NADP+ 2,3-oxidoreductase |
Comments: |
Catalyses the reaction in the reverse direction. This enzyme from Streptomyces collinus is specific for (E)-but-2-enoyl-CoA, and is proposed to provide butanoyl-CoA as a starter unit for straight-chain fatty acid biosynthesis. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB |
References: |
1. |
Wallace, K.K., Bao, Z.Y., Dai, H., Digate, R., Schuler, G., Speedie, M.K. and Reynolds, K.A. Purification of crotonyl-CoA reductase from Streptomyces collinus and cloning, sequencing and expression of the corresponding gene in Escherichia coli. Eur. J. Biochem. 233 (1995) 954–962. [DOI] [PMID: 8521864] |
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[EC 1.3.1.86 created 2011] |
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EC |
1.3.1.109 |
Accepted name: |
butanoyl-CoA dehydrogenase complex (NAD+, ferredoxin) |
Reaction: |
butanoyl-CoA + 2 NAD+ + 2 reduced ferredoxin [iron-sulfur] cluster = (E)-but-2-enoyl-CoA + 2 NADH + 2 oxidized ferredoxin [iron-sulfur] cluster
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Glossary: |
(E)-but-2-enoyl-CoA = crotonyl-CoA |
Other name(s): |
bifurcating butyryl-CoA dehydrogenase; butyryl-CoA dehydrogenase/Etf complex; Etf-Bcd complex; bifurcating butanoyl-CoA dehydrogenase; butanoyl-CoA dehydrogenase/Etf complex; butanoyl-CoA dehydrogenase (NAD+, ferredoxin) |
Systematic name: |
butanoyl-CoA:NAD+, ferredoxin oxidoreductase |
Comments: |
The enzyme is a complex of a flavin-containing dehydrogenase component (Bcd) and an electron-transfer flavoprotein dimer (EtfAB). The enzyme complex, isolated from the bacteria Acidaminococcus fermentans and butanoate-producing Clostridia species, couples the exergonic reduction of (E)-but-2-enoyl-CoA to butanoyl-CoA by NADH to the endergonic reduction of ferredoxin by NADH, using electron bifurcation to overcome the steep energy barrier in ferredoxin reduction. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc |
References: |
1. |
Li, F., Hinderberger, J., Seedorf, H., Zhang, J., Buckel, W. and Thauer, R.K. Coupled ferredoxin and crotonyl coenzyme A (CoA) reduction with NADH catalyzed by the butyryl-CoA dehydrogenase/Etf complex from Clostridium kluyveri. J. Bacteriol. 190 (2008) 843–850. [DOI] [PMID: 17993531] |
2. |
Aboulnaga el,-H., Pinkenburg, O., Schiffels, J., El-Refai, A., Buckel, W. and Selmer, T. Effect of an oxygen-tolerant bifurcating butyryl coenzyme A dehydrogenase/electron-transferring flavoprotein complex from Clostridium difficile on butyrate production in Escherichia coli. J. Bacteriol. 195 (2013) 3704–3713. [DOI] [PMID: 23772070] |
3. |
Chowdhury, N.P., Mowafy, A.M., Demmer, J.K., Upadhyay, V., Koelzer, S., Jayamani, E., Kahnt, J., Hornung, M., Demmer, U., Ermler, U. and Buckel, W. Studies on the mechanism of electron bifurcation catalyzed by electron transferring flavoprotein (Etf) and butyryl-CoA dehydrogenase (Bcd) of Acidaminococcus fermentans. J. Biol. Chem. 289 (2014) 5145–5157. [DOI] [PMID: 24379410] |
4. |
Chowdhury, N.P., Kahnt, J. and Buckel, W. Reduction of ferredoxin or oxygen by flavin-based electron bifurcation in Megasphaera elsdenii. FEBS J. 282 (2015) 3149–3160. [DOI] [PMID: 25903584] |
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[EC 1.3.1.109 created 2015, modified 2021] |
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EC |
1.3.8.6 |
Accepted name: |
glutaryl-CoA dehydrogenase (ETF) |
Reaction: |
glutaryl-CoA + electron-transfer flavoprotein = crotonyl-CoA + CO2 + reduced electron-transfer flavoprotein (overall reaction) (1a) glutaryl-CoA + electron-transfer flavoprotein = (E)-glutaconyl-CoA + reduced electron-transfer flavoprotein (1b) (E)-glutaconyl-CoA = crotonyl-CoA + CO2 |
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For diagram of Benzoyl-CoA catabolism, click here |
Glossary: |
(E)-glutaconyl-CoA = (2E)-4-carboxybut-2-enoyl-CoA
crotonyl-CoA = (E)-but-2-enoyl-CoA |
Other name(s): |
glutaryl coenzyme A dehydrogenase; glutaryl-CoA:(acceptor) 2,3-oxidoreductase (decarboxylating); glutaryl-CoA dehydrogenase |
Systematic name: |
glutaryl-CoA:electron-transfer flavoprotein 2,3-oxidoreductase (decarboxylating) |
Comments: |
Contains FAD. The enzyme catalyses the oxidation of glutaryl-CoA to glutaconyl-CoA (which remains bound to the enzyme), and the decarboxylation of the latter to crotonyl-CoA (cf. EC 7.2.4.5, glutaconyl-CoA decarboxylase). FAD is the electron acceptor in the oxidation of the substrate, and its reoxidation by electron-transfer flavoprotein completes the catalytic cycle. The anaerobic, sulfate-reducing bacterium Desulfococcus multivorans contains two glutaryl-CoA dehydrogenases: a decarboxylating enzyme (this entry), and a non-decarboxylating enzyme that only catalyses the oxidation to glutaconyl-CoA [EC 1.3.99.32, glutaryl-CoA dehydrogenase (acceptor)]. |
Links to other databases: |
BRENDA, EAWAG-BBD, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 37255-38-2 |
References: |
1. |
Besrat, A., Polan, C.E. and Henderson, L.M. Mammalian metabolism of glutaric acid. J. Biol. Chem. 244 (1969) 1461–1467. [PMID: 4304226] |
2. |
Hartel, U., Eckel, E., Koch, J., Fuchs, G., Linder, D. and Buckel, W. Purification of glutaryl-CoA dehydrogenase from Pseudomonas sp., an enzyme involved in the anaerobic degradation of benzoate. Arch. Microbiol. 159 (1993) 174–181. [PMID: 8439237] |
3. |
Dwyer, T.M., Zhang, L., Muller, M., Marrugo, F. and Frerman, F. The functions of the flavin contact residues, αArg249 and βTyr16, in human electron transfer flavoprotein. Biochim. Biophys. Acta 1433 (1999) 139–152. [DOI] [PMID: 10446367] |
4. |
Rao, K.S., Albro, M., Dwyer, T.M. and Frerman, F.E. Kinetic mechanism of glutaryl-CoA dehydrogenase. Biochemistry 45 (2006) 15853–15861. [DOI] [PMID: 17176108] |
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[EC 1.3.8.6 created 1972 as EC 1.3.99.7, transferred 2012 to EC 1.3.8.6, modified 2013, modified 2019] |
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EC |
4.2.1.120 |
Accepted name: |
4-hydroxybutanoyl-CoA dehydratase |
Reaction: |
4-hydroxybutanoyl-CoA = (E)-but-2-enoyl-CoA + H2O |
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For diagram of the 3-hydroxypropanoate/4-hydroxybutanoate cycle and dicarboxylate/4-hydroxybutanoate cycle in archaea, click here |
Glossary: |
4-hydroxybutanoyl-CoA = 4-hydroxybutyryl-CoA
(E)-but-2-enoyl-CoA = crotonyl-CoA |
Systematic name: |
4-hydroxybutanoyl-CoA hydro-lyase |
Comments: |
Contains FAD and a [4Fe-4S] iron-sulfur cluster. The enzyme has been characterized from several microorganisms, including Clostridium kluyveri, where it participates in succinate fermentation [1,2], Clostridium aminobutyricum, where it participates in 4-aminobutyrate degradation [3,4], and Metallosphaera sedula, where it participates in the 3-hydroxypropionate/4-hydroxybutyrate cycle, an autotrophic CO2 fixation pathway found in some thermoacidophilic archaea [5]. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB |
References: |
1. |
Bartsch, R.G. and Barker, H.A. A vinylacetyl isomerase from Clostridium kluyveri. Arch. Biochem. Biophys. 92 (1961) 122–132. [DOI] [PMID: 13687513] |
2. |
Scherf, U., Sohling, B., Gottschalk, G., Linder, D. and Buckel, W. Succinate-ethanol fermentation in Clostridium kluyveri: purification and characterisation of 4-hydroxybutyryl-CoA dehydratase/vinylacetyl-CoA Δ3-Δ2-isomerase. Arch. Microbiol. 161 (1994) 239–245. [PMID: 8161284] |
3. |
Scherf, U. and Buckel, W. Purification and properties of an iron-sulfur and FAD-containing 4-hydroxybutyryl-CoA dehydratase/vinylacetyl-CoA Δ3-Δ2-isomerase from Clostridium aminobutyricum. Eur. J. Biochem. 215 (1993) 421–429. [DOI] [PMID: 8344309] |
4. |
Muh, U., Cinkaya, I., Albracht, S.P. and Buckel, W. 4-Hydroxybutyryl-CoA dehydratase from Clostridium aminobutyricum: characterization of FAD and iron-sulfur clusters involved in an overall non-redox reaction. Biochemistry 35 (1996) 11710–11718. [DOI] [PMID: 8794752] |
5. |
Berg, I.A., Kockelkorn, D., Buckel, W. and Fuchs, G. A 3-hydroxypropionate/4-hydroxybutyrate autotrophic carbon dioxide assimilation pathway in Archaea. Science 318 (2007) 1782–1786. [DOI] [PMID: 18079405] |
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[EC 4.2.1.120 created 2009] |
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EC |
5.3.3.3 |
Accepted name: |
vinylacetyl-CoA Δ-isomerase |
Reaction: |
vinylacetyl-CoA = (E)-but-2-enoyl-CoA |
Glossary: |
(E)-but-2-enoyl-CoA = crotonyl-CoA |
Other name(s): |
vinylacetyl coenzyme A Δ-isomerase; vinylacetyl coenzyme A isomerase; Δ3-cis-Δ2-trans-enoyl-CoA isomerase |
Systematic name: |
vinylacetyl-CoA Δ3-Δ2-isomerase |
Comments: |
Also acts on 3-methyl-vinylacetyl-CoA. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9023-73-8 |
References: |
1. |
Lynen, F., Knappe, J., Lorch, E., Jütting, G. and Ringelmann, E. Die biochemische Funktion des Biotins. Angew. Chem. 71 (1959) 481–486. |
2. |
Rilling, H.C. and Coon, M.J. The enzymatic isomerization of α-methylvinylacetyl coenzyme A and the specificity of a bacterial α-methylcrotonyl coenzyme A carboxylase. J. Biol. Chem. 235 (1960) 3087–3092. [PMID: 13741692] |
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[EC 5.3.3.3 created 1961, modified 2011] |
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