http://en.people.cn/n3/2024/0126/c90000-20127375.htm
https://www.science.org/doi/10.1126/science.adj3484
The biosynthesis of paclitaxel involves the formation of a highly functionalized diterpenoid core skeleton (baccatin III) and the subsequent assembly of a phenylisoserinoyl side chain. The group of Yan Jianbin at the CAAS Institute of Agricultural Genomics in Shenzhen has identified a bifunctional cytochrome P450 enzyme (Taxane oxetanase, TOT) that catalyzes an oxidative rearrangement in paclitaxel oxetane formation, representing a previously unknown enzyme mechanism for oxetane ring formation. The team created a screening strategy based on the taxusin biosynthesis pathway and uncovered the enzyme responsible for the taxane oxidation of the C9-position (T9αH), and reconstituted a biosynthetic pathway for the production of baccatin III in tobacco.