IUBMB Enzyme Nomenclature


Accepted name: 3β-hydroxysteroid-4α-carboxylate 3-dehydrogenase (decarboxylating)

Reaction: a 3β-hydroxysteroid-4α-carboxylate + NAD(P)+ = a 3-oxosteroid + CO2 + NAD(P)H

For diagram of reaction click here

Other name(s): 3β-hydroxy-4β-methylcholestenecarboxylate 3-dehydrogenase (decarboxylating); 3β-hydroxy-4β-methylcholestenoate dehydrogenase; sterol 4α-carboxylic decarboxylase; sterol-4 -carboxylate 3-dehydrogenase (decarboxylating) (ambiguous); ERG26 (gene name); NSDHL (gene name).

Systematic name: 3β-hydroxysteroid-4α-carboxylate:NAD(P)+ 3-oxidoreductase (decarboxylating)

Comments: The enzyme catalyses the decarboxylation of the C-4 carbon and the dehydrogenation of a 3β hydroxyl at the C-3 carbon of 3β-hydroxysteroid-4α-carboxylates. It is involved in zymosterol and cholesterol biosynthesis.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 71822-23-6


1. Brady, D.R., Crowder, R.D. and Hayes, W.J. Mixed function oxidases in sterol metabolism. Source of reducing equivalents. J. Biol. Chem. 255 (1980) 10624-10629. [PMID: 7430141]

2. Rahimtula, A.D. and Gaylor, J.L. Partial purification of a microsomal sterol 4α-carboxylic acid decarboxylase. J. Biol. Chem. 247 (1972) 9-15. [PMID: 4401584]

3. Gachotte, D., Barbuch, R., Gaylor, J., Nickel, E. and Bard, M. Characterization of the Saccharomyces cerevisiae ERG26 gene encoding the C-3 sterol dehydrogenase (C-4 decarboxylase) involved in sterol biosynthesis. Proc. Natl. Acad. Sci. USA 95 (1998) 13794-13799. [PMID: 9811880]

4. Caldas, H. and Herman, G.E. NSDHL, an enzyme involved in cholesterol biosynthesis, traffics through the Golgi and accumulates on ER membranes and on the surface of lipid droplets. Hum. Mol. Genet. 12 (2003) 2981-2991. [PMID: 14506130]

[EC created 1978, modified 2002, modified 2012]

Return to EC 1.1.1 home page
Return to EC 1.1 home page
Return to EC 1 home page
Return to Enzymes home page
Return to IUBMB Biochemical Nomenclature home page