title: Microcin 25, a novel antimicrobial peptide produced by Escherichia coli.
abstract: Microcin 25, a peptide antibiotic excreted by an Escherichia coli strain isolated from human feces, was purified to homogeneity and characterized. Composition analysis and data from gel filtration indicated that microcin 25 may contain 20 amino acid residues. It has a blocked amino-terminal end. Microcin synthesis and immunity are plasmid determined, and the antibiotic was produced in minimal medium when the cultures entered the stationary phase of growth. The peptide appears to interfere with cell division, since susceptible cells filamented when exposed to it. This response does not seem to be mediated by the SOS system.
authors.affiliation: Departamento de Bioquímica de la Nutrición, Instituto Superior de Investigaciones Biológicas (Consejo Nacional de Investigaciones Científicas y Técnicas-UNT), Tucumán, Argentina.
authors.forename: R A
authors.initials: RA
authors.lastname: Salomón
authors.forename: R N
authors.initials: RN
authors.lastname: Farías
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000900:Anti-Bacterial Agents / Q000096:biosynthesis* / Q000302:isolation & purification / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development; D001430:Bacteriocins / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D002850:Chromatography, Gel; D004926:Escherichia coli / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D005243:Feces / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D010957:Plasmids
chemical_list: D000596:Amino Acids; D000900:Anti-Bacterial Agents; D001430:Bacteriocins; C020411:microcin