Figure 1.

Putative taxol biosynthetic pathway. (A) The source and formation of the taxane core. (B) The modification of the core taxane skeleton. (C) The synthesis of the β-phenylalanyl-CoA side chain and the assembly of taxol. The solid arrows show the identified steps. The dotted arrows show the unknown steps. Steps marked by red color represent the uncharacterized enzymatic reactions. Dotted frame represents intermediate steps of the pathway where several enzymes and the order of their reactions are unknown.