Characterization of a novel aphid prenyltransferase displaying dual geranyl/farnesyl diphosphate synthase activity

摘要

We report on the cDNA cloning and characterizationof a novel short-chain isoprenyl diphosphate synthase from theaphid Myzus persicae. Of the three IPPS cDNAs we cloned,two yielded prenyltransferase activity following expression inEscherichia coli; these cDNAs encode identical proteins exceptfor the presence, in one of them, of an N-terminal mitochondrialtargeting peptide. Although the aphid enzyme was predicted tobe a farnesyl diphosphate synthase by BLASTP analysis,rMpIPPS, when isopentenyl diphosphate and dimethylallyldiphosphate are supplied as substrates, typically generated geranyldiphosphate (C10) as its main product, along with significantquantities of farnesyl diphosphate (C15). Analysis of anMpIPPS homology model pointed to substitutions that couldconfer GPP/FPP synthase activity to the aphid enzyme.