title: The microcin J25 beta-hairpin region is important for antibiotic uptake but not for RNA polymerase and respiration inhibition.
abstract: The antibiotic microcin J25 (MccJ25) was cleaved by hydrolysis with thermolysin giving a two-chain peptide (MccJ25-Th19) of 10 and 9 amino acid residues. MccJ25-Th19 with deep modifications in beta-hairpin region had no effect on Escherichia coli growth, but still inhibited RNA polymerase in vitro and oxygen consumption in Salmonella strains. MccJ25-Th19 showed antibiotic activity on E. coli transformed with plasmids containing either fhuA or sbmA genes, which code for proteins involved in MccJ25 transport. These results suggest that an intact beta-hairpin region is crucial for MccJ25 import but not for inhibition of E. coli RNA polymerase or oxygen consumption in Salmonella strains.
authors.affiliation: Departamento de Bioquímica de la Nutrición, Instituto Superior de Investigaciones Biológicas (Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad Nacional de Tucumán), Chacabuco 461, 4000 San Miguel de Tucumán, Tucumán, Argentina.
authors.forename: Augusto
authors.initials: A
authors.lastname: Bellomio
authors.forename: Paula A
authors.initials: PA
authors.lastname: Vincent
authors.forename: Beatriz F
authors.initials: BF
authors.lastname: de Arcuri
authors.forename: Raúl A
authors.initials: RA
authors.lastname: Salomón
authors.forename: Roberto D
authors.initials: RD
authors.lastname: Morero
authors.forename: Ricardo N
authors.initials: RN
authors.lastname: Farías
mesh_terms: D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics / Q000494:pharmacology; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism; D001430:Bacteriocins / Q000235:genetics / Q000493:pharmacokinetics* / Q000494:pharmacology*; D012321:DNA-Directed RNA Polymerases / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D004926:Escherichia coli / Q000187:drug effects / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011991:Receptors, Virus / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000493:pharmacokinetics / Q000494:pharmacology; D012475:Salmonella / Q000187:drug effects / Q000502:physiology*; D013045:Species Specificity; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D001430:Bacteriocins; D029968:Escherichia coli Proteins; C050900:FhuA protein, E coli; D011991:Receptors, Virus; D011994:Recombinant Proteins; C020411:microcin; D012321:DNA-Directed RNA Polymerases; D010100:Oxygen