The microcin J25 beta-hairpin region is important for antibiotic uptake but not for RNA polymerase and respiration inhibition.
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.
Bellomio
Augusto
A
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.
Vincent
Paula A
PA
de Arcuri
Beatriz F
BF
Salomón
Raúl A
RA
Morero
Roberto D
RD
Farías
Ricardo N
RN
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
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