IUBMB Enzyme Nomenclature


Accepted name: 3β-hydroxycholanate 3-dehydrogenase (NAD+)

Reaction: isolithocholate + NAD+ = 3-oxo-5β-cholan-24-oate + NADH + H+

Glossary: isolithocholate = 3β-hydroxy-5β-cholan-24-oate

Other name(s): 3β-hydroxysteroid dehydrogenase

Systematic name: isolithocholate:NAD+ 3-oxidoreductase

Comments: This bacterial enzyme is involved, along with EC, 3α-hydroxycholanate dehydrogenase (NAD+), or EC, 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, 3β-hydroxycholanate 3-dehydrogenase (NADP+).

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:


1. Edenharder, R., Pfutzner, A. and Hammann, R. Characterization of NAD-dependent 3 α- and 3 β-hydroxysteroid dehydrogenase and of NADP-dependent 7 β-hydroxysteroid dehydrogenase from Peptostreptococcus productus, Biochim. Biophys. Acta 1004 (1989) 230-238. [PMID: 2752021]

2. Edenharder, R. and Pfutzner, M. Partial purification and characterization of an NAD-dependent 3 β-hydroxysteroid dehydrogenase from Clostridium innocuum, Appl. Environ. Microbiol. 55 (1989) 1656-1659. [PMID: 2764572]

3. 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]

[EC created 2016]

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