title: Unique animal prenyltransferase with monoterpene synthase activity.
abstract: Monoterpenes are structurally diverse natural compounds that play an essential role in the chemical ecology of a wide array of organisms. A key enzyme in monoterpene biosynthesis is geranyl diphosphate synthase (GPPS). GPPS is an isoprenyl diphosphate synthase that catalyzes a single electrophilic condensation reaction between dimethylallyl diphosphate (C(5)) and isopentenyl diphosphate (C(5)) to produce geranyl diphosphate (GDP; C(10)). GDP is the universal precursor to all monoterpenes. Subsequently, monoterpene synthases are responsible for the transformation of GDP to a variety of acyclic, monocyclic, and bicyclic monoterpene products. In pheromone-producing male Ips pini bark beetles (Coleoptera: Scolytidae), the acyclic monoterpene myrcene is required for the production of the major aggregation pheromone component, ipsdienol. Here, we report monoterpene synthase activity associated with GPPS of I. pini. Enzyme assays were performed on recombinant GPPS to determine the presence of monoterpene synthase activity, and the reaction products were analyzed by coupled gas chromatography-mass spectrometry. The functionally expressed recombinant enzyme produced both GDP and myrcene, making GPPS of I. pini a bifunctional enzyme. This unique insect isoprenyl diphosphate synthase possesses the functional plasticity that is characteristic of terpene biosynthetic enzymes of plants, contributing toward the current understanding of product specificity of the isoprenoid pathway.
authors.affiliation: Department of Biochemistry and Molecular Biology/MS 330, University of Nevada, Reno, Reno, NV 89557-0014, USA.
authors.forename: Anna B
authors.initials: AB
authors.lastname: Gilg
authors.forename: Claus
authors.initials: C
authors.lastname: Tittiger
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Blomquist
mesh_terms: D000080462:Acyclic Monoterpenes; D000475:Alkenes / Q000378:metabolism; D019883:Alkyl and Aryl Transferases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001517:Coleoptera / Q000201:enzymology / Q000378:metabolism; D017931:DNA Primers; D004122:Dimethylallyltranstransferase / Q000235:genetics / Q000378:metabolism*; D011756:Diphosphates / Q000378:metabolism*; D004224:Diterpenes / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000378:metabolism; D006900:Hydroxylation; D007700:Kinetics; D039821:Monoterpenes / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000378:metabolism; D015183:Restriction Mapping
chemical_list: D000080462:Acyclic Monoterpenes; D000475:Alkenes; D017931:DNA Primers; D011756:Diphosphates; D004224:Diterpenes; D039821:Monoterpenes; D011994:Recombinant Proteins; C511282:geranyl diphosphate; C509595:myrcene; D019883:Alkyl and Aryl Transferases; C108877:terpene synthase; D004122:Dimethylallyltranstransferase