Reaction catalyzed by 3alpha-hydroxysteroid 3-dehydrogenase (Si-specific) (1.1.1.50)
+
2
NAD(P)H
+
2
=
+
2
NAD(P)+
5alpha-dihydroprogesterone
+
2 NAD(P)H
+
2 H+
=
pregnan-3alpha,20beta-diol
+
2 NAD(P)+