[Cloning and functional characterization of a cDNA encoding isopentenyl diphosphate isomerase involved in taxol biosynthesis in Taxus media].

Taxol is one of the most potent anti-cancer agents, which is extracted from the plants of Taxus species. Isopentenyl diphosphate isomerase (IPI) catalyzes the reversible transformation between IPP and DMAPP, both of which are the general 5-carbon precursors for taxol biosynthesis. In the present study, a new gene encoding IPI was cloned from Taxus media (namely TmIPI with the GenBank Accession Number KP970677) for the first time. The full-length cDNA of TmIPI was 1 232 bps encoding a polypeptide with 233 amino acids, in which the conserved domain Nudix was found. Bioinformatic analysis indicated that the sequence of TmIPI was highly similar to those of other plant IPI proteins, and the phylogenetic analysis showed that there were two clades of plant IPI proteins, including IPIs of angiosperm plants and IPIs of gymnosperm plants. TmIPI belonged to the clade of gymnosperm plant IPIs, and this was consistent with the fact that Taxus media is a plant species of gymnosperm. Southern blotting analysis demonstrated that there was a gene family of IPI in Taxus media. Finally, functional verification was applied to identify the function of TmIPI. The results showed that biosynthesis of ß-carotenoid was enhanced by overexpressing TmIPI in the engineered E. coli strain, and this suggested that TmIPI might be a key gene involved in isoprenoid/terpenoid biosynthesis.