title: Antibiotic resistance mechanisms inform discovery: identification and characterization of a novel amycolatopsis strain producing ristocetin.
abstract: Discovering new antibiotics is a major scientific challenge, made increasingly urgent by the continued development of resistance in bacterial pathogens. A fundamental understanding of the mechanisms of bacterial antibiotic resistance will be vital for the future discovery or design of new, more effective antibiotics. We have exploited our intimate knowledge of the molecular mechanism of glycopeptide antibiotic resistance in the harmless bacterium Streptomyces coelicolor to develop a new two-step cell wall bioactivity screen, which efficiently identified a new actinomycete strain containing a previously uncharacterized glycopeptide biosynthetic gene cluster. The screen first identifies natural product extracts capable of triggering a generalized cell wall stress response and then specifically selects for glycopeptide antibacterials by assaying for the induction of glycopeptide resistance genes. In this study, we established a diverse natural product extract library from actinomycete strains isolated from locations with widely varying climates and ecologies, and we screened them using the novel two-step bioassay system. The bioassay ultimately identified a single strain harboring the previously unidentified biosynthetic gene cluster for the glycopeptide ristocetin, providing a proof of principle for the effectiveness of the screen. This is the first report of the ristocetin biosynthetic gene cluster, which is predicted to include some interesting and previously uncharacterized enzymes. By focusing on screening libraries of microbial extracts, this strategy provides the certainty that identified producer strains are competent for growth and biosynthesis of the detected glycopeptide under laboratory conditions.
authors.affiliation: Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom.
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Truman
authors.affiliation: Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Min Jung
authors.initials: MJ
authors.lastname: Kwun
authors.affiliation: Center for Neutraceutical and Pharmaceutical Materials, Myongji University, Yongin, Republic of Korea.
authors.forename: Jinhua
authors.initials: J
authors.lastname: Cheng
authors.affiliation: Center for Neutraceutical and Pharmaceutical Materials, Myongji University, Yongin, Republic of Korea.
authors.forename: Seung Hwan
authors.initials: SH
authors.lastname: Yang
authors.affiliation: Center for Neutraceutical and Pharmaceutical Materials, Myongji University, Yongin, Republic of Korea Division of Bioscience and Bioinformatics, College of Natural Science, Myongji University, Yongin, Republic of Korea jwsuh@mju.ac.kr hh309@cam.ac.uk.
authors.forename: Joo-Won
authors.initials: JW
authors.lastname: Suh
authors.affiliation: Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom jwsuh@mju.ac.kr hh309@cam.ac.uk.
authors.forename: Hee-Jeon
authors.initials: HJ
authors.lastname: Hong
mesh_terms: D000192:Actinomycetales / Q000187:drug effects / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002473:Cell Wall / Q000187:drug effects / Q000378:metabolism; D024881:Drug Resistance, Bacterial / Q000235:genetics; D005810:Multigene Family / Q000235:genetics; D012310:Ristocetin / Q000378:metabolism*; D013302:Streptomyces / Q000187:drug effects / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D012310:Ristocetin