Reaction: (2R,3S)-3-isopropylmalate = (2S)-2-isopropylmalate (overall reaction)
(1a) (2R,3S)-3-isopropylmalate = 2-isopropylmaleate + H2O
(1b) 2-isopropylmaleate + H2O = (2S)-2-isopropylmalate
For diagram of reaction click here.
Glossary: α-isopropylmalate = (2S)-2-isopropylmalate
β-isopropylmalate = (2R,3S)-3-isopropylmalate
Other name(s): (2R,3S)-3-isopropylmalate hydro-lyase; β-isopropylmalate dehydratase; isopropylmalate isomerase; α-isopropylmalate isomerase; 3-isopropylmalate hydro-lyase
Systematic name: (2R,3S)-3-isopropylmalate hydro-lyase (2-isopropylmaleate-forming)
Comments: Forms part of the leucine biosynthesis pathway. The enzyme brings about the interconversion of the two isomers of isopropylmalate. It contains an iron-sulfur cluster.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 37290-72-5
1. Gross, S.R., Burns, R.O. and Umbarger, H.E. The biosynthesis of leucine. II. The enzymic isomerization of β-carboxy-β-hydroxyisocaproate and α-hydroxy-β-carboxyisocaproate. Biochemistry 2 (1963) 1046-1052. [PMID: 14087357]
2. Calvo, J. M., Stevens, C. M., Kalyanpur, M. G., and Umbarger, H. E. The absolute configuration of α-hydroxy-β-carboxyisocaproic acid (3-isopropylmalic acid), an intermediate in leucine biosynthesis. Biochemistry 3 (1964) 2024-2027. [PMID: 14269331]
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]
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