Ketol-acid reductoisomerase
In enzymology, a ketol-acid reductoisomerase is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are -2,3-dihydroxy-3-methylbutanoate and NADP+, whereas its 3 products are -2-hydroxy-2-methyl-3-oxobutanoate, NADPH, and H+.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is -2,3-dihydroxy-3-methylbutanoate:NADP+ oxidoreductase . Other names in common use include dihydroxyisovalerate dehydrogenase , acetohydroxy acid isomeroreductase, ketol acid reductoisomerase, alpha-keto-beta-hydroxylacyl reductoisomerase, 2-hydroxy-3-keto acid reductoisomerase, acetohydroxy acid reductoisomerase, acetolactate reductoisomerase, dihydroxyisovalerate dehydrogenase, isomeroreductase, and reductoisomerase. This enzyme participates in valine, leucine and isoleucine biosynthesis and pantothenate and coa biosynthesis.As of late 2007, 4 structures have been solved for this class of enzymes, with PDB accession codes,,, and.