Ketol-Acid Reductoisomerase

**Definition:** An enzyme that catalyzes the oxidation of (R)-2,3-dihydroxy-3-methylbutanoate to (S)-2-hydroxy-2-methyl-3-oxobutanoate in the presence of NADP. It is involved in the biosynthesis of VALINE; LEUCINE; ISOLEUCINE; pentothenate and COENZYME A. This enzyme was formerly classified as EC 1.1.1.89.

**Tree numbers:** - D08.811.682.047.820.487

**Synonyms:** - Acetohydroxy Acid Isomeroreductase - Alpha-Acetohydroxyacid Isomeroreductase - Dihydroxyisovalerate Dehydrogenase (Isomerizing) - Hydroxyacid Reductoisomerase - Isomeroreductase