title: Functional characterization of myrcene hydroxylases from two geographically distinct Ips pini populations.
abstract: Ips pini bark beetles use myrcene hydroxylases to produce the aggregation pheromone component, ipsdienol, from myrcene. The enantiomeric ratio of pheromonal ipsdienol is an important prezygotic mating isolation mechanism of I. pini and differs among geographically distinct populations. We explored the substrate and product ranges of myrcene hydroxylases (CYP9T2 and CYP9T3) from reproductively-isolated western and eastern I. pini. The two cytochromes P450 share 94% amino acid identity. CYP9T2 mRNA levels were not induced in adults exposed to myrcene-saturated atmosphere. Functional assays of recombinant enzymes showed both hydroxylated myrcene, (+)- and (-)-α-pinene, 3-carene, and R-(+)-limonene, but not α-phellandrene, (-)-β-pinene, γ-terpinene, or terpinolene, with evidence that CYP9T2 strongly preferred myrcene over other substrates. They differed in the enantiomeric ratios of ipsdienol produced from myrcene, and in the products resulting from different α-pinene enantiomers. These data provide new information regarding bark beetle pheromone evolution and factors affecting cytochrome P450 structure-function relationships.
authors: Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557, USA.
authors: Minmin
authors: M
authors: Song
authors: Amy C
authors: AC
authors: Kim
authors: Andrew J
authors: AJ
authors: Gorzalski
authors: Marina
authors: M
authors: MacLean
authors: Sharon
authors: S
authors: Young
authors: Matthew D
authors: MD
authors: Ginzel
authors: Gary J
authors: GJ
authors: Blomquist
authors: Claus
authors: C
authors: Tittiger
mesh_terms: D000080462:Acyclic Monoterpenes; D000475:Alkenes / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001517:Coleoptera / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D005260:Female; D005843:Geography; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008297:Male; D006899:Mixed Function Oxygenases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D039821:Monoterpenes / Q000378:metabolism*; D016415:Sequence Alignment; D013379:Substrate Specificity
chemical_list: D000080462:Acyclic Monoterpenes; D000475:Alkenes; D019476:Insect Proteins; D039821:Monoterpenes; C509595:myrcene; D006899:Mixed Function Oxygenases