Arabidopsis CYP85A2, a cytochrome P450, mediates the Baeyer-Villiger oxidation of castasterone to brassinolide in brassinosteroid biosynthesis.
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.
Kim
Tae-Wuk
TW
Department of Life Science, Chung-Ang University, Seoul 156-756, Korea.
Hwang
Jung-Yun
JY
Kim
Young-Soo
YS
Joo
Se-Hwan
SH
Chang
Soo Chul
SC
Lee
June Seung
JS
Takatsuto
Suguru
S
Kim
Seong-Ki
SK
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*
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