title: Identification and Heterologous Expression of the Topopyrone Nonaketide Synthase Gene from Phoma sp.
abstract: Non-reducing iterative type I polyketide synthase genes, pnk1 and pnk2, were cloned from the fungus Phoma sp. BAUA2861, which produces the topoisomerase I inhibitors, topopyrones A to D. Heterologous expression of these polyketide synthase genes under the α-amylase promoter in Aspergillus oryzae was carried out to identify their functions. The pnk2 transformant produced topopyrones C, D, and haematommone. Therefore, the pnk2 gene was found to encode for the topopyrone nonaketide synthase.
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kashiwa
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Ebizuka
authors.forename: Isao
authors.initials: I
authors.lastname: Fujii
mesh_terms: D000880:Anthraquinones / Q000032:analysis / Q000378:metabolism; D001203:Ascomycota / Q000201:enzymology*; D004264:DNA Topoisomerases, Type I / Q000378:metabolism; D006801:Humans; D015394:Molecular Structure; D048630:Polyketide Synthases / Q000235:genetics / Q000378:metabolism*; D011753:Pyrones / Q000032:analysis / Q000378:metabolism; D059004:Topoisomerase I Inhibitors / Q000032:analysis* / Q000378:metabolism
chemical_list: D000880:Anthraquinones; D011753:Pyrones; D059004:Topoisomerase I Inhibitors; C417102:topopyrone A; C417105:topopyrone B; C417104:topopyrone C; C417103:topopyrone D; D048630:Polyketide Synthases; D004264:DNA Topoisomerases, Type I