title: exo-Brevicomin biosynthetic pathway enzymes from the Mountain Pine Beetle, Dendroctonus ponderosae.
abstract: exoBrevicomin (exo-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]octane) is an important semiochemical for a number of beetle species, including the highly destructive Mountain Pine Beetle (Dendroctonus ponderosae). It is also found in other insects and the African elephant. Despite its significance, very little is known about its biosynthesis. A recent microarray analysis implicated a small cluster of three D. ponderosae genes in exo-brevicomin biosynthesis, two of which had identifiable open reading frames (Aw et al., 2010; BMC Genomics 11:215). Here we report further expression profiling of two genes in that cluster and functional analysis of their recombinantly-produced enzymes. One encodes a short-chain dehydrogenase that used NAD(P)(+) as a co-factor to catalyze the oxidation of (Z)-6-nonen-2-ol to (Z)-6-nonen-2-one. We therefore named the enzyme (Z)-6-nonen-2-ol dehydrogenase (ZnoDH). The other encodes the cytochrome P450, CYP6CR1, which epoxidized (Z)-6-nonen-2-one to 6,7-epoxynonan-2-one with very high specificity and substrate selectivity. Both the substrates and products of the two enzymes are intermediates in the exo-brevicomin biosynthetic pathway. Thus, ZnoDH and CYP6CR1 are enzymes that apparently catalyze the antepenultimate and penultimate steps in the exo-brevicomin biosynthetic pathway, respectively.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557, USA. Electronic address: min_min28@hotmail.com.
authors.forename: Minmin
authors.initials: M
authors.lastname: Song
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557, USA. Electronic address: delaplain@gmail.com.
authors.forename: Patrick
authors.initials: P
authors.lastname: Delaplain
authors.affiliation: Department of Chemistry, University of Nevada, Reno, NV 89557, USA. Electronic address: trangn@unr.edu.
authors.forename: Trang T
authors.initials: TT
authors.lastname: Nguyen
authors.affiliation: Department of Chemistry, University of Nevada, Reno, NV 89557, USA. Electronic address: xibeibessie@gmail.com.
authors.forename: Xibei
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557, USA. Electronic address: liyha@gmail.com.
authors.forename: Leah
authors.initials: L
authors.lastname: Wickenberg
authors.affiliation: Department of Chemistry, University of Nevada, Reno, NV 89557, USA. Electronic address: cjeffrey@unr.edu.
authors.forename: Christopher
authors.initials: C
authors.lastname: Jeffrey
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557, USA. Electronic address: garyb@cabnr.unr.edu.
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Blomquist
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557, USA. Electronic address: crt@unr.edu.
authors.forename: Claus
authors.initials: C
authors.lastname: Tittiger
mesh_terms: D000596:Amino Acids; D000818:Animals; D053898:Biosynthetic Pathways; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000378:metabolism*; D002384:Catalysis; D001517:Coleoptera / Q000201:enzymology*; D004950:Esterases / Q000737:chemistry; D005260:Female; D020869:Gene Expression Profiling; D007659:Ketones; D008297:Male; D008969:Molecular Sequence Data; D010675:Pheromones / Q000096:biosynthesis*
chemical_list: C101379:6-nonen-2-one; D000596:Amino Acids; D019086:Bridged Bicyclo Compounds, Heterocyclic; D007659:Ketones; D010675:Pheromones; D004950:Esterases; C012219:brevicomin
keywords: Bark beetle; Dehydrogenase; Functional assay; Metabolic pathway; P450; Pheromone; exo-Brevicomin