Reaction: pyruvate + CoA + 2 oxidized ferredoxin = acetyl-CoA + CO2 + 2 reduced ferredoxin + 2 H+
For diagram of the 3-hydroxypropanoate/4-hydroxybutanoate cycle and dicarboxylate/4-hydroxybutanoate cycle in archaea, click here
Other name(s): pyruvate oxidoreductase (ambiguous); pyruvate synthetase (ambiguous); pyruvate:ferredoxin oxidoreductase; pyruvic-ferredoxin oxidoreductase; 2-oxobutyrate synthase; α-ketobutyrate-ferredoxin oxidoreductase; 2-ketobutyrate synthase; α-ketobutyrate synthase; 2-oxobutyrate-ferredoxin oxidoreductase; 2-oxobutanoate:ferredoxin 2-oxidoreductase (CoA-propionylating); 2-oxobutanoate:ferredoxin 2-oxidoreductase (CoA-propanoylating); pyruvate synthase
Systematic name: pyruvate:ferredoxin 2-oxidoreductase (CoA-acetylating)
Comments: Contains thiamine diphosphate and [4Fe-4S] clusters. The enzyme, common in bacteria, archaea, and some algae, catalyses the reversible decarboxylation of pyruvate with the formation of acetyl-CoA. Enzymes from different organisms catalyse the reaction in different directions depending on their metabolic needs. The enzyme also decarboxylates 2-oxobutanoate with lower efficiency, but shows no activity with 2-oxoglutarate. In some organisms ferredoxin may be replaced by the flavin mononucleotide (FMN)-containing flavodoxin under conditions of low iron and high oxygen (cf. EC 1.2.8.1, pyruvate synthase (flavodoxin)). This enzyme is a member of the 2-oxoacid oxidoreductases, a family of enzymes that oxidatively decarboxylate different 2-oxoacids to form their CoA derivatives, and are differentiated based on their substrate specificity. For examples of other members of this family, see EC 1.2.7.3, 2-oxoglutarate synthase and EC 1.2.7.7, 3-methyl-2-oxobutanoate dehydrogenase (ferredoxin).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9082-51-3
References:
1. Evans, M.C.W. and Buchanan, B.B. Photoreduction of ferredoxin and its use in carbon dioxide fixation by a subcellular system from a photosynthetic bacterium. Proc. Natl. Acad. Sci. USA 53 (1965) 1420-1425. [PMID: 5217644]
2. Gehring, U. and Arnon, D.I. Purification and properties of α-ketoglutarate synthase from a photosynthetic bacterium. J. Biol. Chem. 247 (1972) 6963-6969. [PMID: 4628267]
3. Uyeda, K. and Rabinowitz, J.C. Pyruvate-ferredoxin oxidoreductase. 3. Purification and properties of the enzyme. J. Biol. Chem. 246 (1971) 3111-3119. [PMID: 5574389]
4. Uyeda, K. and Rabinowitz, J.C. Pyruvate-ferredoxin oxidoreductase. IV. Studies on the reaction mechanism. J. Biol. Chem. 246 (1971) 3120-3125. [PMID: 4324891]
5. Charon, M.-H., Volbeda, A., Chabriere, E., Pieulle, L. and Fontecilla-Camps, J.C. Structure and electron transfer mechanism of pyruvate:ferredoxin oxidoreductase. Curr. Opin. Struct. Biol. 9 (1999) 663-669. [PMID: 10607667]
6. Cossu, M., Catlin, D., Elliott, S.J., Metcalf, W.W. and Nair, S.K. Structural organization of pyruvate: ferredoxin oxidoreductase from the methanogenic archaeon Methanosarcina acetivorans, Structure 32 (2024) 1963-1972.e3. [PMID: 39265575]
7. Yakunin, A.F. and Hallenbeck, P.C. Purification and characterization of pyruvate oxidoreductase from the photosynthetic bacterium Rhodobacter capsulatus, Biochim. Biophys Acta 1409 (1998) 39-49. [PMID: 9804883]