IUBMB Enzyme Nomenclature

EC 1.14.14.178

Accepted name: steroid 22S-hydroxylase

Reaction: (1) a C27-steroid + O2 + [reduced NADPH—hemoprotein reductase] = a (22S)-22-hydroxy-C27-steroid + 2 H2O + [oxidized NADPH—hemoprotein reductase]
(2) a C28-steroid + O2 + [reduced NADPH—hemoprotein reductase] = a (22S)-22-hydroxy-C28-steroid + 2 H2O + [oxidized NADPH—hemoprotein reductase]
(3) a C29-steroid + O2 + [reduced NADPH—hemoprotein reductase] = a (22S)-22-hydroxy-C29-steroid + 2 H2O + [oxidized NADPH—hemoprotein reductase]

Other name(s): CYP90B1 (gene name); DWF4 (gene name); steroid C-22 hydroxylase

Systematic name: steroid,NADPH—hemoprotein reductase:oxygen 22S-oxidoreductase (hydroxylating)

Comments: This plant cytochrome P-450 (heme thiolate) enzyme participates in the biosynthesis of brassinosteroids. While in vivo substrates include C28-steroids such as campestanol, campesterol, and 6-oxocampestanol, the enzyme is able to catalyse the C-22 hydroxylation of a variety of C27, C28 and C29 steroids.

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

References:

1. Asami, T., Mizutani, M., Fujioka, S., Goda, H., Min, Y.K., Shimada, Y., Nakano, T., Takatsuto, S., Matsuyama, T., Nagata, N., Sakata, K. and Yoshida, S. Selective interaction of triazole derivatives with DWF4, a cytochrome P450 monooxygenase of the brassinosteroid biosynthetic pathway, correlates with brassinosteroid deficiency in planta. J. Biol. Chem. 276 (2001) 25687-25691. [PMID: 11319239]

2. Choe, S., Fujioka, S., Noguchi, T., Takatsuto, S., Yoshida, S. and Feldmann, K.A. Overexpression of DWARF4 in the brassinosteroid biosynthetic pathway results in increased vegetative growth and seed yield in Arabidopsis. Plant J. 26 (2001) 573-582. [PMID: 11489171]

3. Asami, T., Mizutani, M., Shimada, Y., Goda, H., Kitahata, N., Sekimata, K., Han, S.Y., Fujioka, S., Takatsuto, S., Sakata, K. and Yoshida, S. Triadimefon, a fungicidal triazole-type P450 inhibitor, induces brassinosteroid deficiency-like phenotypes in plants and binds to DWF4 protein in the brassinosteroid biosynthesis pathway. Biochem. J. 369 (2003) 71-76. [PMID: 12350224]

4. Fujita, S., Ohnishi, T., Watanabe, B., Yokota, T., Takatsuto, S., Fujioka, S., Yoshida, S., Sakata, K. and Mizutani, M. Arabidopsis CYP90B1 catalyses the early C-22 hydroxylation of C27, C28 and C29 sterols. Plant J. 45 (2006) 765-774. [PMID: 16460510]

5. Ohnishi, T., Watanabe, B., Sakata, K. and Mizutani, M. CYP724B2 and CYP90B3 function in the early C-22 hydroxylation steps of brassinosteroid biosynthetic pathway in tomato. Biosci. Biotechnol. Biochem. 70 (2006) 2071-2080. [PMID: 16960392]

[EC 1.14.14.178 created 2022]


Return to EC 1.14.14 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