title: An enzyme catalyzing O-prenylation of the glucose moiety of fusicoccin A, a diterpene glucoside produced by the fungus Phomopsis amygdali.
abstract: Isoprenoids form the largest family of compounds found in nature. Isoprenoids are often attached to other moieties such as aromatic compounds, indoles/tryptophan, and flavonoids. These reactions are catalyzed by three phylogenetically distinct prenyltransferases: soluble aromatic prenyltransferases identified mainly in actinobacteria, soluble indole prenyltransferases mostly in fungi, and membrane-bound prenyltransferases in various organisms. Fusicoccin A (FC A) is a diterpene glycoside produced by the plant-pathogenic fungus Phomopsis amygdali and has a unique O-prenylated glucose moiety. In this study, we identified for the first time, from a genome database of P. amygdali, a gene (papt) encoding a prenyltransferase that reversibly transfers dimethylallyl diphosphate (DMAPP) to the 6'-hydroxy group of the glucose moiety of FC A to yield an O-prenylated sugar. An in vitro assay with a recombinant enzyme was also developed. Detailed analyses with recombinant PAPT showed that the enzyme is likely to be a monomer and requires no divalent cations. The optimum pH and temperature were 8.0 and 50 °C, respectively. K(m) values were calculated as 0.49±0.037 μM for FC P (a plausible intermediate of FC A biosynthesis) and 8.3±0.63 μM for DMAPP, with a k(cat) of 55.3±3.3×10⁻³ s. The enzyme did not act on representative substrates of the above-mentioned three types of prenyltransferase, but showed a weak transfer activity of geranyl diphosphate to FC P.
authors.affiliation: Graduate School of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan.
authors.forename: Motoyoshi
authors.initials: M
authors.lastname: Noike
authors.forename: Chengwei
authors.initials: C
authors.lastname: Liu
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ono
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Hamano
authors.forename: Tomonobu
authors.initials: T
authors.lastname: Toyomasu
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sassa
authors.forename: Nobuo
authors.initials: N
authors.lastname: Kato
authors.forename: Tohru
authors.initials: T
authors.lastname: Dairi
mesh_terms: D001203:Ascomycota / Q000737:chemistry* / Q000378:metabolism; D055162:Biocatalysis; D004122:Dimethylallyltranstransferase / Q000737:chemistry / Q000378:metabolism*; D005947:Glucose / Q000737:chemistry / Q000378:metabolism*; D006027:Glycosides / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D008968:Molecular Conformation; D054876:Prenylation; D013379:Substrate Specificity
chemical_list: D006027:Glycosides; C007808:fusicoccin; D004122:Dimethylallyltranstransferase; D005947:Glucose