label: steroid 21-monooxygenase activity
label_lc: steroid 21-monooxygenase activity
description: "Catalysis of the reaction: A C(21) steroid + [reduced NADPH--hemoprotein reductase] + O2 = a 21-hydroxy-C(21)-steroid + [oxidized NADPH--hemoprotein reductase] + H2O."