title: Assembly of dimeric variants of coumermycins by tandem action of the four biosynthetic enzymes CouL, CouM, CouP, and NovN.
abstract: Coumermycin A(1) is a member of the aminocoumarin family of antibiotics. Unlike its structural relatives, novobiocin and clorobiocin, coumermycin A(1) is a dimer built on a 3-methyl-2,4-dicarboxypyrrole scaffold and bears two decorated noviose sugar components which are the putative target binding motifs for DNA gyrase. Starting with this scaffold, we have utilized the ligase CouL for mono- and bisamide formation with aminocoumarins to provide substrates for the glycosyltransferase CouM. CouM was subsequently shown to catalyze mono- and bisnoviosylation of the resulting CouL products. CouP was shown to possess 4'-O-methyltransferase activity on products from tandem CouL, CouM assays. A fourth enzyme, NovN, the 3'-O-carbamoyltransferase from the novobiocin operon, was then able to carbamoylate either or both arms of the CouP product. The tandem action of CouL, CouM, CouP, and NovN thus generates a biscarbamoyl analogue of the pseudodimer coumermycin A(1). Starting from alternative dicarboxy scaffolds, these four enzymes can be utilized in tandem to create additional variants of dimeric aminocoumarin antibiotics.
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: Caren L
authors.initials: CL
authors.lastname: Freel Meyers
authors.forename: Markus
authors.initials: M
authors.lastname: Oberthür
authors.forename: Lutz
authors.initials: L
authors.lastname: Heide
authors.forename: Daniel
authors.initials: D
authors.lastname: Kahne
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Walsh
mesh_terms: D049933:Aminocoumarins; D000900:Anti-Bacterial Agents / Q000096:biosynthesis* / Q000737:chemistry* / Q000302:isolation & purification; D002853:Chromatography, Liquid; D003374:Coumarins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D019281:Dimerization; D004926:Escherichia coli / Q000235:genetics; D014644:Genetic Variation; D016695:Glycosyltransferases / Q000378:metabolism; D008025:Ligases / Q000737:chemistry / Q000378:metabolism*; D013058:Mass Spectrometry; D015394:Molecular Structure; D013302:Streptomyces / Q000235:genetics; D013379:Substrate Specificity
chemical_list: D049933:Aminocoumarins; D000900:Anti-Bacterial Agents; D003374:Coumarins; D016695:Glycosyltransferases; D008025:Ligases; C004628:coumermycin