Catalyzes the NADPH-dependent reduction of 2-oxoglutarate and 2-oxobutanoate, leading to the respective 2-hydroxycarboxylate. Cannot use NADH instead of NADPH as a redox partner. Do not catalyze the reverse reactions. 2-hydroxybutanoate + NADP(+) = 2-oxobutanoate + H(+) + NADPH 2-hydroxyglutarate + NADP(+) = 2-oxoglutarate + H(+) + NADPH Binds 1 zinc ion per subunit. Cells lacking this gene show a consistent change in 2-hydroxyglutarate level. Belongs to the iron-containing alcohol dehydrogenase family.