Ketol-acid reductoisomerase

Function

Ketol-acid reductoisomerase (KARI) is a bifunctional enzyme which catalizes two steps in the biosynthesis of branched-chain amino acids. KARI catalyzes the isomerization of alkyls and the NADPH-dependent reduction of a 2-ketoacid^[1]. There are two forms of KARI. A short form – Class I – found in fungi and most bacteria and a long form – Class II – found in plants.