IUBMB Enzyme Nomenclature


Accepted name: (R)-2-hydroxyisocaproyl-CoA dehydratase

Reaction: (R)-2-hydroxy-4-methylpentanoyl-CoA = 4-methylpent-2-enoyl-CoA + H2O

Other name(s): 2-hydroxyisocaproyl-CoA dehydratase; HadBC

Systematic name: (R)-2-hydroxy-4-methylpentanoyl-CoA hydro-lyase

Comments: The enzyme, isolated from the bacterium Peptoclostridium difficile, is involved in the reductive branch of L-leucine fermentation. It catalyses an α/β-dehydration, which depends on the reductive formation of ketyl radicals on the substrate generated by injection of a single electron from the ATP-dependent activator protein HadI.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:


1. Kim, J., Darley, D. and Buckel, W. 2-Hydroxyisocaproyl-CoA dehydratase and its activator from Clostridium difficile. FEBS J. 272 (2005) 550-561. [PMID: 15654892]

2. Knauer, S.H., Buckel, W. and Dobbek, H. Structural basis for reductive radical formation and electron recycling in (R)-2-hydroxyisocaproyl-CoA dehydratase. J. Am. Chem. Soc. 133 (2011) 4342-4347. [PMID: 21366233]

[EC created 2015]

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