2-isopropylmalate synthase

In enzymology, a 2-isopropylmalate synthase is an enzyme that catalyzes the chemical reaction


 * acetyl-CoA + 3-methyl-2-oxobutanoate + H2O $$\rightleftharpoons$$ (2S)-2-isopropylmalate + CoA

The 3 substrates of this enzyme are acetyl-CoA, 3-methyl-2-oxobutanoate, and H2O, whereas its two products are (2S)-2-isopropylmalate and CoA.

This enzyme belongs to the family of transferases, specifically those acyltransferases that convert acyl groups into alkyl groups on transfer. The systematic name of this enzyme class is acetyl-CoA:3-methyl-2-oxobutanoate C-acetyltransferase (thioester-hydrolysing, carboxymethyl-forming). Other names in common use include 3-carboxy-3-hydroxy-4-methylpentanoate 3-methyl-2-oxobutanoate-lyase, (CoA-acetylating), alpha-isopropylmalate synthetase, alpha-isopropylmalate synthase, alpha-isopropylmalic synthetase, isopropylmalate synthase, and isopropylmalate synthetase. This enzyme participates in valine, leucine and isoleucine biosynthesis and pyruvate metabolism. It employs one cofactor, potassium.

Structural studies
As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code.