3-beta-hydroxysteroid dehydrogenase (NAD+)/C4-decarboxylase activity
3-beta-hydroxysteroid dehydrogenase (nad+)/c4-decarboxylase activity
Catalysis of the reaction: a 3-beta-hydroxysteroid-4-alpha-carboxylate + NAD+ = a 3-oxosteroid + CO2 + NADH.