steroid 17-alpha-monooxygenase activity

Catalysis of the reaction: a steroid + AH2 + O2 = a 17a-hydroxysteroid + A + H2O.

17alpha-hydroxylase-C17,20 lyase activity, cytochrome P-450 (P-45017alpha,lyase), cytochrome P450 CYP17, cytochrome P45017alpha, cytochrome p450 XVIIA1 activity, steroid 17-alpha-hydroxylase activity, steroid 17-alpha-hydroxylase-C17-20 lyase activity, steroid 17-alpha-hydroxylase/17,20 lyase activity, steroid 17-alpha-monooxygenase activity, steroid 17alpha-hydroxylase activity, steroid 17alpha-monooxygenase activity, steroid 17alphahydroxylase/17,20 lyase activity, steroid,hydrogen-donor:oxygen oxidoreductase (17alpha-hydroxylating)