title: Expression, purification and crystallization of a plant polyketide cyclase from Cannabis sativa.
abstract: Plant polyketides are a structurally diverse family of natural products. In the biosynthesis of plant polyketides, the construction of the carbocyclic scaffold is a key step in diversifying the polyketide structure. Olivetolic acid cyclase (OAC) from Cannabis sativa L. is the only known plant polyketide cyclase that catalyzes the C2-C7 intramolecular aldol cyclization of linear pentyl tetra-β-ketide-CoA to generate olivetolic acid in the biosynthesis of cannabinoids. The enzyme is also thought to belong to the dimeric α+β barrel (DABB) protein family. However, because of a lack of functional analysis of other plant DABB proteins and low sequence identity with the functionally distinct bacterial DABB proteins, the catalytic mechanism of OAC has remained unclear. To clarify the intimate catalytic mechanism of OAC, the enzyme was overexpressed in Escherichia coli and crystallized using the vapour-diffusion method. The crystals diffracted X-rays to 1.40 Å resolution and belonged to space group P3121 or P3221, with unit-cell parameters a = b = 47.3, c = 176.0 Å. Further crystallographic analysis will provide valuable insights into the structure-function relationship and catalytic mechanism of OAC.
authors.affiliation: Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama, Toyama 930-0194, Japan.
authors.forename: Xinmei
authors.initials: X
authors.lastname: Yang
authors.affiliation: Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama, Toyama 930-0194, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Matsui
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Mori
authors.affiliation: Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, Toyama 930-0194, Japan.
authors.forename: Futoshi
authors.initials: F
authors.lastname: Taura
authors.affiliation: School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga, Shizuoka 422-8526, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Noguchi
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Ikuro
authors.initials: I
authors.lastname: Abe
authors.affiliation: Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama, Toyama 930-0194, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Morita
mesh_terms: D000595:Amino Acid Sequence; D002188:Cannabis / Q000201:enzymology*; D003460:Crystallization; D019751:Intramolecular Transferases / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D012459:Salicylates / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D012459:Salicylates; C112458:olivetolic acid; D019751:Intramolecular Transferases; C575822:olivetolic acid cyclase, Cannabis sativa
keywords: Cannabis sativa; cannabinoids; cyclase; olivetolic acid