IUBMB Enzyme Nomenclature


Accepted name: 3β,22α-dihydroxysteroid 3-dehydrogenase

Reaction: (1) (22S)-22-hydroxycampesterol + [reduced NADPH-hemoprotein reductase] + O2 = (22S)-22-hydroxycampest-4-en-3-one + [oxidized NADPH-hemoprotein reductase] + 2 H2O
(2) 6-deoxoteasterone + [reduced NADPH-hemoprotein reductase] + O2 = 3-dehydro-6-deoxoteasterone + [oxidized NADPH-hemoprotein reductase] + 2 H2O

Glossary: 6-deoxoteasterone = (22R,23R)-5α-campestane-3β,22,23-triol

Other name(s): CYP90A1 (gene name)

Systematic name: 3β,22α-dihydroxysteroid,[reduced NADPH-hemoprotein reductase]:oxygen 3-oxidoreductase

Comments: This cytochrome P-450 (heme-thiolate) enzyme, characterized from the plant Arabidopsis thaliana, catalyses C-3 dehydrogenation of all 3β-hydroxy brassinosteroid synthesis intermediates with 22-hydroxylated or 22,23-dihydroxylated side chains.

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


1. Ohnishi, T., Godza, B., Watanabe, B., Fujioka, S., Hategan, L., Ide, K., Shibata, K., Yokota, T., Szekeres, M. and Mizutani, M. CYP90A1/CPD, a brassinosteroid biosynthetic cytochrome P450 of Arabidopsis, catalyzes C-3 oxidation. J. Biol. Chem. 287 (2012) 31551-31560. [PMID: 22822057]

[EC created 2022]

Return to EC 1.14.19 home page
Return to EC 1.14 home page
Return to EC 1 home page
Return to Enzymes home page
Return to IUBMB Biochemical Nomenclature home page