label: steroid 17-alpha-monooxygenase activity
label_lc: steroid 17-alpha-monooxygenase activity
description: "Catalysis of the reaction: a C21-steroid + O2 + reduced [NADPH--hemoprotein reductase] = a 17alpha-hydroxy-C21-steroid + H+ + H2O + oxidized [NADPH--hemoprotein reductase]."