Reaction catalyzed by ketol-acid reductoisomerase (NADP+) (1.1.1.86)
+
NADPH
+
=
+
NADP+
2-hydroxy-2-methyl-3-oxobutanoate
+
NADPH
+
H+
=
2,3-dihydroxy-2-methyl-butanoate
+
NADP+
