title: Parallel Post-Polyketide Synthase Modification Mechanism Involved in FD-891 Biosynthesis in Streptomyces graminofaciens A-8890.
abstract: To isolate a key polyketide biosynthetic intermediate for the 16-membered macrolide FD-891 (1), we inactivated two biosynthetic genes coding for post-polyketide synthase (PKS) modification enzymes: a methyltransferase (GfsG) and a cytochrome P450 (GfsF). Consequently, FD-892 (2), which lacks the epoxide moiety at C8-C9, the hydroxy group at C10, and the O-methyl group at O-25 of FD-891, was isolated from the gfsF/gfsG double-knockout mutant. In addition, 25-O-methyl-FD-892 (3) and 25-O-demethyl-FD-891 (4) were isolated from the gfsF and gfsG mutants, respectively. We also confirmed that GfsG efficiently catalyzes the methylation of 2 and 4 in vitro. Further, GfsF catalyzed the epoxidation of the double bond at C8-C9 of 2 and 3 and subsequent hydroxylation at C10, to afford 4 and 1, respectively. These results suggest that a parallel post-PKS modification mechanism is involved in FD-891 biosynthesis.
authors.affiliation: Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo, 152-8551, Japan.
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Kudo
authors.affiliation: Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo, 152-8551, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Kawamura
authors.affiliation: Department of Chemistry and Materials Science, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo, 152-8551, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Furuya
authors.affiliation: Department of Chemistry and Materials Science, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo, 152-8551, Japan.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Yamanishi
authors.affiliation: Department of Chemistry and Materials Science, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo, 152-8551, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Motegi
authors.affiliation: Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo, 152-8551, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Komatsubara
authors.affiliation: Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo, 152-8551, Japan.
authors.forename: Mario
authors.initials: M
authors.lastname: Numakura
authors.affiliation: Department of Chemistry, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo, 152-8551, Japan.
authors.forename: Akimasa
authors.initials: A
authors.lastname: Miyanaga
authors.affiliation: Department of Chemistry and Materials Science, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo, 152-8551, Japan. eguchi@chem.titech.ac.jp.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Eguchi
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D004852:Epoxy Compounds / Q000737:chemistry; D006900:Hydroxylation; D007700:Kinetics; D018942:Macrolides / Q000737:chemistry / Q000378:metabolism*; D008745:Methylation; D008780:Methyltransferases / Q000378:metabolism; D005810:Multigene Family; D016297:Mutagenesis, Site-Directed; D048630:Polyketide Synthases / Q000235:genetics / Q000378:metabolism*; D013302:Streptomyces / Q000201:enzymology*
chemical_list: D004852:Epoxy Compounds; D018942:Macrolides; C091118:FD 891; C091119:FD 892; D048630:Polyketide Synthases; D003577:Cytochrome P-450 Enzyme System; D008780:Methyltransferases
keywords: antibiotics; biosynthesis; methyltransferases; natural products; polyketides