title: Arabidopsis CYP85A2, a cytochrome P450, mediates the Baeyer-Villiger oxidation of castasterone to brassinolide in brassinosteroid biosynthesis.
abstract: The conversion of castasterone (CS) to brassinolide (BL), a Baeyer-Villiger oxidation, represents the final and rate-limiting step in the biosynthesis of BL in plants. Heterologously expressed Arabidopsis thaliana CYP85A2 in yeast mediated the conversion of CS to BL as well as the C-6 oxidation of brassinosteroids (BRs). This indicated that CYP85A2 is a bifunctional enzyme that possesses BR C-6 oxidase and BL synthase activity. CYP85A2 is thus a cytochrome P450 that mediates Baeyer-Villiger oxidation in plants. Biochemical, physiological, and molecular genetic analyses of Arabidopsis CYP85A2 loss-of-function and overexpression lines demonstrated that CS has to be a bioactive BR that controls the overall growth and development of Arabidopsis plants. Mutant studies also revealed that BL may not always be necessary for normal growth and development but that Arabidopsis plants acquire great benefit in terms of growth and development in the presence of BL.
authors: Department of Life Science, Chung-Ang University, Seoul 156-756, Korea.
authors: Tae-Wuk
authors: TW
authors: Kim
authors: Jung-Yun
authors: JY
authors: Hwang
authors: Young-Soo
authors: YS
authors: Kim
authors: Se-Hwan
authors: SH
authors: Joo
authors: Soo Chul
authors: SC
authors: Chang
authors: June Seung
authors: JS
authors: Lee
authors: Suguru
authors: S
authors: Takatsuto
authors: Seong-Ki
authors: SK
authors: Kim
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism*; D060406:Brassinosteroids; D002777:Cholestanols / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013260:Steroids, Heterocyclic / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D060406:Brassinosteroids; D002777:Cholestanols; D013260:Steroids, Heterocyclic; C083545:castasterone; D003577:Cytochrome P-450 Enzyme System; C474078:brassinosteroid-6 oxidase 1, Arabidopsis; C474079:brassinosteroid-6 oxidase 2, Arabidopsis; C023623:brassinolide