Vol 54(2020) N 5 p. 719-729; DOI 10.1134/S002689332005009X
R. Sun1,2, J.L. Gao2, H. Chen1*, S. Liu2, Z.Z. Tang1
CbCYP716A261, a New β-Amyrin 28-Hydroxylase Involved in Conyzasaponin Biosynthesis from Conyza blinii1College of Life Science, Sichuan Agricultural University, Ya'an, Sichuan, 625014 China
2College of Biological and Chemical Engineering, Panzhihua University, Panzhihua, Sichuan, 617000 China
Received - 2020-02-08; Revised - 2020-02-08; Accepted - 2020-03-13
Conyzasaponins produced by the traditional Chinese herb Conyza blinii are oleanane-type saponins with a wide range of biological activities. Here, we identified a gene, designated CbCYP716A261, encoding a β-amyrin 28-hydroxylase in conyzasaponins biosynthesis. Ten full putative CYP sequences were isolated from Conyza blinii transcript tags. The CbCYP716A261 gene product was selected as the putative β-amyrin 28-hydroxylase by phylogenetic analysis and transcriptional activity analysis of methyl jasmonate-treated Conyza blinii. To identify the enzymatic activity, we performed enzymatic activity experiments in vitro and in vivo. The HPLC results revealed that CbCYP716A261 catalyzes the hydroxylation of β-amyrin at the C-28 position to yield oleanolic acid. Our findings provide new information about the conyzasaponin biosynthesis pathway and widen the list of isolated β-amyrin 28-hydroxylases.
cytochrome P450, CbCYP716A261, β-amyrin, conyzasaponin, oleanolic acid