7alpha-hydroxysteroid dehydrogenase that catalyzes the NADP(+)-dependent oxidation of the 7alpha-hydroxy group of 7alpha-hydroxysteroids, such as cholate, chenodeoxycholate, glycochenodeoxycholate and taurochenodeoxycholate, to the corresponding 7-oxosteroids (PubMed:22198717, PubMed:24810359). Is also able to catalyze the reverse reduction reactions (PubMed:22198717). Together with 7beta-HSDH encoded in the adjacent gene, is likely involved in the epimerization of the hydroxy group at C-7 of primary bile acids through 7-keto bile acid intermediates (PubMed:22198717). cholate + NADP(+) = 3alpha,12alpha-dihydroxy-7-oxo-5beta-cholanate + H(+) + NADPH chenodeoxycholate + NADP(+) = 7-oxolithocholate + H(+) + NADPH 3alpha,7alpha-dihydroxy-12-oxo-5beta-cholanate + NADP(+) = 7,12-dioxo-lithocholate + H(+) + NADPH 7alpha-hydroxy-3,12-dioxo-5beta-cholanate + NADP(+) = dehydrocholate + H(+) + NADPH glycochenodeoxycholate + NADP(+) = 7-oxoglycolithocholate + H(+) + NADPH NADP(+) + taurochenodeoxycholate = 7-oxotaurolithocholate + H(+) + NADPH Activated by metal ions such as Mg(2+), Na(+) and K(+). kcat is 343000 sec(-1) for the oxidation of cholate. kcat is 13600 sec(-1) for the reduction of 3alpha,12alpha-dihydroxy-7-oxo-5beta-cholanate. kcat is 9390 sec(-1) for the oxidation of chenodeoxycholate. kcat is 977 sec(-1) for the reduction of 7-oxolithocholate. kcat is 222000 sec(-1) for the oxidation of 3alpha,7alpha-dihydroxy-12-oxo-5beta-cholanate. kcat is 30600 sec(-1) for the reduction of 7,12-dioxo-lithocholate. kcat is 22600 sec(-1) for the reduction of dehydrocholate (PubMed:22198717). kcat is 21.2 sec(-1) for the oxidation of chenodeoxycholate. kcat is 19.6 sec(-1) for the oxidation of glycochenodeoxycholate. kcat is 11.5 sec(-1) for the oxidation of taurochenodeoxycholate (PubMed:24810359). Shows a maximum of activity between pH 7.5 and 8.0 both in the oxidation reaction of cholate and in the reduction reaction of 3alpha,12alpha-dihydroxy-7-oxo-5beta-cholanate. Optimum temperature is 40 degrees Celsius. No activity is detected above 60 degrees Celsius. Homotetramer (PubMed:22198717, PubMed:26961171). A dynamic equilibrium between dimers and tetramers seems to exist (PubMed:26961171). Up-regulated by bile acids, when grown in the presence of deoxycholate or chenodeoxycholate. Could be a promising candidate for further applications in the epimerization reaction of bile acids at the C-7 position and thus may be used as a biocatalyst for the synthesis of bile acids derivatives of pharmacological interest. Belongs to the short-chain dehydrogenases/reductases (SDR) family.