IUBMB Enzyme Nomenclature


Accepted name: 2-hydroxyisobutanoyl-CoA mutase

Reaction: 2-hydroxy-2-methylpropanoyl-CoA = (S)-3-hydroxybutanoyl-CoA

Glossary: 2-hydroxy-2-methylpropanoyl-CoA = 2-hydroxyisobutanoyl-CoA

Other name(s): hcmAB (gene names)

Systematic name: 2-hydroxy-2-methylpropanoyl-CoA mutase

Comments: The enzyme, characterized from the bacterium Aquincola tertiaricarbonis, uses radical chemistry to rearrange the positions of both a methyl group and a hydroxyl group. It consists of two subunits, the smaller one containing a cobalamin cofactor. It plays a central role in the degradation of assorted substrates containing a tert-butyl moiety.

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


1. Yaneva, N., Schuster, J., Schafer, F., Lede, V., Przybylski, D., Paproth, T., Harms, H., Muller, R.H. and Rohwerder, T. Bacterial acyl-CoA mutase specifically catalyzes coenzyme B12-dependent isomerization of 2-hydroxyisobutyryl-CoA and (S)-3-hydroxybutyryl-CoA. J. Biol. Chem. 287 (2012) 15502-15511. [PMID: 22433853]

2. Kurteva-Yaneva, N., Zahn, M., Weichler, M.T., Starke, R., Harms, H., Muller, R.H., Strater, N. and Rohwerder, T. Structural basis of the stereospecificity of bacterial B12-dependent 2-hydroxyisobutyryl-CoA mutase. J. Biol. Chem. 290 (2015) 9727-9737. [PMID: 25720495]

[EC created 2016 as EC, transferred 2017 to EC]

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