IUBMB Enzyme Nomenclature


Accepted name: 3α-hydroxy bile acid-CoA-ester 3-dehydrogenase

Reaction: a 3α-hydroxy bile acid CoA ester + NAD+ = a 3-oxo bile acid CoA ester + NADH + H+

Other name(s): baiA1 (gene name); baiA2 (gene name); baiA3 (gene name)

Systematic name: 3α-hydroxy-bile-acid-CoA-ester:NAD+ 3-oxidoreductase

Comments: This bacterial enzyme is involved in the 7-dehydroxylation process associated with bile acid degradation. The enzyme has very little activity with unconjugated bile acid substrates. It has similar activity with choloyl-CoA, chenodeoxycholoyl-CoA, deoxycholoyl-CoA, and lithocholoyl-CoA.

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


1. Mallonee, D.H., Lijewski, M.A. and Hylemon, P.B. Expression in Escherichia coli and characterization of a bile acid-inducible 3α-hydroxysteroid dehydrogenase from Eubacterium sp. strain VPI 12708. Curr. Microbiol. 30 (1995) 259-263. [PMID: 7766153]

2. Bhowmik, S., Jones, D.H., Chiu, H.P., Park, I.H., Chiu, H.J., Axelrod, H.L., Farr, C.L., Tien, H.J., Agarwalla, S. and Lesley, S.A. Structural and functional characterization of BaiA, an enzyme involved in secondary bile acid synthesis in human gut microbe. Proteins 82 (2014) 216-229. [PMID: 23836456]

[EC created 2016]

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