IUBMB Enzyme Nomenclature


Accepted name: 2-isopropylmalate synthase

Reaction: acetyl-CoA + 3-methyl-2-oxobutanoate + H2O = (2S)-2-isopropylmalate + CoA

For diagram of reaction click here.

Other name(s): 3-carboxy-3-hydroxy-4-methylpentanoate 3-methyl-2-oxobutanoate-lyase (CoA-acetylating); α-isopropylmalate synthetase; α-isopropylmalate synthase; α-isopropylmalic synthetase; isopropylmalate synthase; isopropylmalate synthetase

Systematic name: acetyl-CoA:3-methyl-2-oxobutanoate C-acetyltransferase (thioester-hydrolysing, carboxymethyl-forming)

Comments: Requires K+.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9030-98-2


1. Kohlhaw, G., Leary, T.R. and Umbarger, H.E. α-Isopropylmalate synthase from Salmonella typhimurium. Purification and properties. J. Biol. Chem. 244 (1969) 2218-2225. [PMID: 4976555]

2. Webster, R.E. and Gross, S.R. The α-isopropylmalate synthetase of Neurospora. I. The kinetics and end product control of α-isopropylmalate synthetase function. Biochemistry 4 (1965) 2309-2327.

3. Cole, F.E., Kalyanpur, M. G. and Stevens, C. M. Absolute configuration of α-isopropylmalate and the mechanism of its conversion to β-isopropylmalate in the biosynthesis of leucine. Biochemistry 12 (1973) 3346-3350. [PMID: 4270046]

[EC created 1972 as EC, transferred 2002 to EC]

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