title: Engineered biosynthesis of glycosylated derivatives of narbomycin and evaluation of their antibacterial activities.
abstract: A 14-membered macrolide antibiotic narbomycin produced from Streptomyces venezuelae ATCC 15439 is composed of polyketide macrolactone ring and D-desosamine as a deoxysugar moiety, which acts as an important determinant of its antibacterial activity. In order to generate diverse glycosylated derivatives of narbomycin, expression plasmids carrying different deoxysugar biosynthetic gene cassettes and the gene encoding a substrate-flexible glycosyltransferase DesVII were constructed and introduced into S. venezuelae YJ003 mutant strain bearing a deletion of thymidine-5'-diphospho-D-desosamine biosynthetic gene cluster. The resulting recombinants of S. venezuelae produced a range of new analogs of narbomycin, which possess unnatural sugar moieties instead of native deoxysugar D-desosamine. The structures of narbomycin derivatives were determined through nuclear magnetic resonance spectroscopy and mass spectrometry analyses and their antibacterial activities were evaluated in vitro against erythromycin-susceptible and -resistant Enterococcus faecium and Staphylococcus aureus. Substitution with L-rhamnose or 3-O-demethyl-D-chalcose was demonstrated to exhibit greater antibacterial activity than narbomycin and the clinically relevant erythromycin. This work provides new insight into the functions of deoxysugar biosynthetic enzymes and structure-activity relationships of the sugar moieties attached to the macrolides and demonstrate the potential of combinatorial biosynthesis for the generation of new macrolides carrying diverse sugars with increased antibacterial activities.
authors.affiliation: Interdisciplinary Programs of Bioengineering, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Ah Reum
authors.initials: AR
authors.lastname: Han
authors.forename: Pramod B
authors.initials: PB
authors.lastname: Shinde
authors.forename: Je Won
authors.initials: JW
authors.lastname: Park
authors.forename: Jaeyong
authors.initials: J
authors.lastname: Cho
authors.forename: So Ra
authors.initials: SR
authors.lastname: Lee
authors.forename: Yeon Hee
authors.initials: YH
authors.lastname: Ban
authors.forename: Young Ji
authors.initials: YJ
authors.lastname: Yoo
authors.forename: Eun Ji
authors.initials: EJ
authors.lastname: Kim
authors.forename: Eunji
authors.initials: E
authors.lastname: Kim
authors.forename: Sung Ryeol
authors.initials: SR
authors.lastname: Park
authors.forename: Byung-Gee
authors.initials: BG
authors.lastname: Kim
authors.forename: Dong Gun
authors.initials: DG
authors.lastname: Lee
authors.forename: Yeo Joon
authors.initials: YJ
authors.lastname: Yoon
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D016984:Enterococcus faecium / Q000187:drug effects; D005818:Genetic Engineering / Q000379:methods*; D006031:Glycosylation; D016695:Glycosyltransferases / Q000235:genetics / Q000378:metabolism; D018942:Macrolides / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D009154:Mutation; D010957:Plasmids; D013211:Staphylococcus aureus / Q000187:drug effects; D013302:Streptomyces / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D018942:Macrolides; C010488:narbomycin; D016695:Glycosyltransferases