Reaction: isolithocholate + NADP+ = 3-oxo-5β-cholan-24-oate + NADPH + H+
Glossary: isolithocholate = 3β-hydroxy-5β-cholan-24-oate
Other name(s): 3β-hydroxysteroid dehydrogenase (ambiguous)
Systematic name: isolithocholate:NADP+ 3-oxidoreductase
Comments: This bacterial enzyme is involved, along with EC 22.214.171.124, 3α-hydroxycholanate dehydrogenase (NAD+), or EC 126.96.36.1992, 3α-hydroxycholanate dehydrogenase (NADP+), in the modification of secondary bile acids to form 3β-bile acids (also known as iso-bile acids). The enzyme catalyses the reaction in the reduction direction in vivo. Also acts on related 3-oxo bile acids. cf. EC 188.8.131.521, 3β-hydroxycholanate 3-dehydrogenase (NAD+).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
1. Akao, T., Akao, T., Hattori, M., Namba, T. and Kobashi, K. 3 β-Hydroxysteroid dehydrogenase of Ruminococcus sp. from human intestinal bacteria. J. Biochem. 99 (1986) 1425-1431. [PMID: 3458705]
2. Devlin, A.S. and Fischbach, M.A. A biosynthetic pathway for a prominent class of microbiota-derived bile acids. Nat. Chem. Biol. 11 (2015) 685-690. [PMID: 26192599]