title: Antibiotics GE23077, novel inhibitors of bacterial RNA polymerase. I. Taxonomy, isolation and characterization.
abstract: GE 23077 factors A1, A2, B1 and B2 are novel antibiotics isolated from fermentation broths of an Actinomadura sp. strain. GE23077 antibiotics are cyclic peptides, which inhibit Escherichia coli RNA polymerase at nM concentrations. Both rifampicin-sensitive and rifampicin-resistant polymerases are inhibited, whereas E. coli DNA polymerase and wheat germ RNA polymerase are substantially not affected. In spite of the potent activity on the enzyme, the antibiotics generally show poor activity against whole cell bacteria. The spectrum of activity is restricted to Moraxella catarrhalis, including clinical isolates, with partial activity against Neisseria gonorrhoeae and Mycobacterium smegmatis.
authors.affiliation: Vicuron Pharmaceuticals, Via R. Lepetit 34, 21040 Gerenzano, Varese, Italy.
authors.forename: Ismaela
authors.initials: I
authors.lastname: Ciciliato
authors.forename: Emiliana
authors.initials: E
authors.lastname: Corti
authors.forename: Edoardo
authors.initials: E
authors.lastname: Sarubbi
authors.forename: Stefania
authors.initials: S
authors.lastname: Stefanelli
authors.forename: Luciano
authors.initials: L
authors.lastname: Gastaldo
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Montanini
authors.forename: Michael
authors.initials: M
authors.lastname: Kurz
authors.forename: Daniele
authors.initials: D
authors.lastname: Losi
authors.forename: Flavia
authors.initials: F
authors.lastname: Marinelli
authors.forename: Enrico
authors.initials: E
authors.lastname: Selva
mesh_terms: D000900:Anti-Bacterial Agents / Q000145:classification / Q000302:isolation & purification* / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects / Q000201:enzymology; D002851:Chromatography, High Pressure Liquid; D012321:DNA-Directed RNA Polymerases / Q000037:antagonists & inhibitors*; D004791:Enzyme Inhibitors / Q000145:classification / Q000302:isolation & purification* / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology; D005285:Fermentation; D019384:Nucleic Acid Synthesis Inhibitors; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D019384:Nucleic Acid Synthesis Inhibitors; D012321:DNA-Directed RNA Polymerases