7alpha-hydroxysteroid dehydrogenase that catalyzes the NADP(+)-dependent oxidation of the 7alpha-hydroxy group of 7alpha-hydroxysteroids, such as the major human bile acids cholate and chenodeoxycholate, to the corresponding 7-oxosteroids (PubMed:8050999, PubMed:11947357). Is thus liley involved in the metabolism of primary bile acids (PubMed:8050999). cholate + NADP(+) = 3alpha,12alpha-dihydroxy-7-oxo-5beta-cholanate + H(+) + NADPH chenodeoxycholate + NADP(+) = 7-oxolithocholate + H(+) + NADPH Homotetramer. Up-regulated by bile acids, such as cholate and chenodeoxycholate. Maximally expressed during the early stationary phase of growth. Belongs to the short-chain dehydrogenases/reductases (SDR) family.