3-hydroxy-3-methyl-2-oxobutanoate + NADPH + H(+) => (2R)-2,3-dihydroxy-3-methylbutanoate + NADP(+)
3-hydroxy-3-methyl-2-oxobutanoate + nadph + h(+) => (2r)-2,3-dihydroxy-3-methylbutanoate + nadp(+)
3-hydroxy-3-methyl-2-oxobutanoate + NADPH + H(+) => (2R)-2,3-dihydroxy-3-methylbutanoate + NADP(+)
3-hydroxy-3-methyl-2-oxobutanoate + nadph + h(+) => (2r)-2,3-dihydroxy-3-methylbutanoate + nadp(+)