This gene encodes a member of the aldo/keto reductase superfamily, which consists of more than 40 known enzymes and proteins. These enzymes catalyze the conversion of aldehydes and ketones to their corresponding alcohols using NADH and/or NADPH as cofactors. The enzymes display overlapping but distinct substrate specificity. This enzyme binds bile acid with high affinity, and shows minimal 3-alpha-hydroxysteroid dehydrogenase activity. This gene shares high sequence identity with three other gene members and is clustered with those three genes at chromosome 10p15-p14. Three transcript variants encoding two different isoforms have been found for this gene. [provided by RefSeq, Dec 2011],catalytic activity:Androsterone + NAD(P)(+) = 5-alpha-androstane-3,17-dione + NAD(P)H.,catalytic activity:Trans-1,2-dihydrobenzene-1,2-diol + NADP(+) = catechol + NADPH.,enzyme regulation:Inhibited by hexestrol with an IC(50) of 2.8 uM, 1,10-phenanthroline with an IC(50) of 2100 uM, 1,7-phenanthroline with an IC(50) of 1500 uM, flufenamic acid with an IC(50) of 0.9 uM, indomethacin with an IC(50) of 75 uM, ibuprofen with an IC(50) of 6.9 uM, lithocholic acid with an IC(50) of 0.07 uM, ursodeoxycholic acid with an IC(50) of 0.08 uM and chenodeoxycholic acid with an IC(50) of 0.13 uM.,function:Works in concert with the 5-alpha/5-beta-steroid reductases to convert steroid hormones into the 3-alpha/5-alpha and 3-alpha/5-beta-tetrahydrosteroids. Catalyzes the inactivation of the most potent androgen 5-alpha-dihydrotestosterone (5-alpha-DHT) to 5-alpha-androstane-3-alpha,17-beta-diol (3-alpha-diol). Has a high bile-binding ability.,similarity:Belongs to the aldo/keto reductase family.,
