title: Structure of microcin B-like compounds produced by Pseudomonas syringae and species specificity of their antibacterial action.
abstract: Escherichia coli microcin B (Ec-McB) is a posttranslationally modified antibacterial peptide containing multiple oxazole and thiazole heterocycles and targeting the DNA gyrase. We have found operons homologous to the Ec-McB biosynthesis-immunity operon mcb in recently sequenced genomes of several pathovars of the plant pathogen Pseudomonas syringae, and we produced two variants of P. syringae microcin B (Ps-McB) in E. coli by heterologous expression. Like Ec-McB, both versions of Ps-McB target the DNA gyrase, but unlike Ec-McB, they are active against various species of the Pseudomonas genus, including human pathogen P. aeruginosa. Through analysis of Ec-McB/Ps-McB chimeras, we demonstrate that three centrally located unmodified amino acids of Ps-McB are sufficient to determine activity against Pseudomonas, likely by allowing specific recognition by a transport system that remains to be identified. The results open the way for construction of McB-based antibacterial molecules with extended spectra of biological activity.
authors.affiliation: Institute of Gene Biology of the Russian Academy of Sciences, Moscow, Russia.
authors.forename: Mikhail
authors.initials: M
authors.lastname: Metelev
authors.forename: Marina
authors.initials: M
authors.lastname: Serebryakova
authors.forename: Dmitry
authors.initials: D
authors.lastname: Ghilarov
authors.forename: Youfu
authors.initials: Y
authors.lastname: Zhao
authors.forename: Konstantin
authors.initials: K
authors.lastname: Severinov
mesh_terms: D000900:Anti-Bacterial Agents / Q000096:biosynthesis / Q000737:chemistry / Q000494:pharmacology*; D001430:Bacteriocins / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D006801:Humans; D009876:Operon; D011549:Pseudomonas / Q000145:classification / Q000187:drug effects*; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D044224:Pseudomonas syringae / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D013045:Species Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D053719:Tandem Mass Spectrometry; D059005:Topoisomerase II Inhibitors
chemical_list: D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D059005:Topoisomerase II Inhibitors; C020411:microcin