title: Heterologous biosynthesis of amidated polyketides with novel cyclization regioselectivity from oxytetracycline polyketide synthase.
abstract: Heterologous expression of the minimal oxytetracycline polyketide synthase and the amidotransferase OxyD in Streptomyces coelicolor strain CH999 afforded two novel amidated polyketides, WJ85 (4) and WJ85b (5). WJ85 is a C-9 unreduced decaketide that is primed by a malonamyl starter unit. WJ85 is cyclized via an unusual C-11 to C-16 intramolecular aldol condensation not observed among known aromatic polyketides. The structures of WJ85 and the previously characterized WJ35 suggest that the presence of an amide starter unit has a profound effect on the cyclization regioselectivity and reactivity of a polyketide backbone. WJ85b is an anthraquinone and is an oxidized product of WJ85.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California, USA.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Zhang
authors.forename: Kenji
authors.initials: K
authors.lastname: Watanabe
authors.forename: Clay C C
authors.initials: CC
authors.lastname: Wang
authors.forename: Yi
authors.initials: Y
authors.lastname: Tang
mesh_terms: D003500:Cyclization; D018942:Macrolides / Q000737:chemistry / Q000302:isolation & purification*; D015394:Molecular Structure; D010118:Oxytetracycline / Q000378:metabolism; D048630:Polyketide Synthases / Q000378:metabolism*; D013302:Streptomyces / Q000201:enzymology* / Q000235:genetics*
chemical_list: D018942:Macrolides; D048630:Polyketide Synthases; D010118:Oxytetracycline