A New Farnesyl Diphosphate Synthase Gene fromTaxus mediaRehder: Cloning, Characterization and Functional Complementation

Abstract

AbstractFarnesyl diphosphate synthase (FPS; EC 2.5.1.10) catalyzes the production of 15‐carbon farnesyl diphosphate which is a branch‐point intermediate for many terpenoids. This reaction is considered to be a rate‐limiting step in terpenoid biosynthesis. Here we report for the first time the cloning of a new full‐length cDNA encoding farnesyl diphosphate synthase from a gymnosperm plant species,Taxus mediaRehder, designated asTmFPS1.The full‐length cDNA ofTmFPS1(GenBank accession number: AY461811) was 1 464 bp with a 1 056‐bp open reading frame encoding a 351‐amino acid polypeptide with a calculated molecular weight of 40.3 kDa and a theoretical pI of 5.07. Bioinformatic analysis revealed that TmFPS1 contained all five conserved domains of prenyltransferases, and showed homology to other FPSs of plant origin. Phylogenetic analysis showed that farnesyl diphosphate synthases can be divided into two groups: one of prokaryotic origin and the other of eukaryotic origin. TmFPS1 was grouped with FPSs of plant origin. Homology‐based structural modeling showed that TmFPS1 had the typical spatial structure of FPS, whose most prominent structural feature is the arrangement of 13 core helices around a large central cavity in which the catalytic reaction takes place. Our bioinformatic analysis strongly suggests thatTmFPS1is a functional gene. Southern blot analysis revealed thatTmFPS1belongs to a smallFPSgene family inT. media.Northern blot analysis indicated thatTmFPS1is expressed in all tested tissues, including the needles, stems and roots ofT. media.Subsequently, functional complementation withTmFPS1in a FPS‐deficient mutant yeast demonstrated thatTmFPS1did encode farnesyl diphosphate synthase, which rescued the yeast mutant. This study will be helpful in future investigations aiming at understanding the detailed role of FPS in terpenoid biosynthesis flux control at the molecular genetic level.(Managing editor: Wei Wang)