98%
921
2 minutes
20
Microcins are ribosomally encoded small peptide antibiotics produced by Gram(-) enterobacteria. Microcin production-biosynthesis, maturation and secretion to the medium-is encoded by gene clusters organized in operons. Production of the best known plasmid-encoded microcins (MccB, MccC and MccJ) switches on when cells reach the stationary growth phase. This production is doubly regulated at transcriptional level by (a). the growth phase: microcin operons silent/repressed during exponential growth are induced/derepressed when cells sense nutrient starvation and stop exponential growth, and (b). global bacterial regulators acting as inducers or repressors of operon expression. The role played by these regulators (CRP, EmrR, IHF, H-NS, LRP, OmpR, Sigma-38 and SpoT) in the expression of specific microcin operons is reviewed.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/s0300-9084(02)01452-9 | DOI Listing |
Microbiologyopen
June 2024
Department of Biological Sciences, Munster Technological University, Bishopstown, Cork, Ireland.
Traditional bacteriocin screening methods often face limitations due to diffusion-related challenges in agar matrices, which can prevent the peptides from reaching their target organism. Turbidimetric techniques offer a solution to these issues, eliminating diffusion-related problems and providing an initial quantification of bacteriocin efficacy in producer organisms. This study involved screening the cell-free supernatant (CFS) from eight uncharacterized asymptomatic bacteriuria (ABU) isolates and Escherichia coli 83972 for antimicrobial activity against clinical uropathogenic E.
View Article and Find Full Text PDFMicrobiologyopen
April 2024
School of Nursing and Health Sciences, Faculty of Health Sciences and Wellbeing, University of Sunderland, Sunderland, UK.
We present a comprehensive sequence and bioinformatic analysis of the prototypical microcin plasmid, pMccb17, which includes a definitive sequence for the microcin operon, mcb. Microcin B17 (MccB17) is a ribosomally synthesized and posttranslationally modified peptide produced by Escherichia coli. It inhibits bacterial DNA gyrase similarly to quinolone antibiotics.
View Article and Find Full Text PDFAppl Environ Microbiol
November 2023
Section of Molecular Microbiology, Imperial College London, London, United Kingdom.
Probiotic bacteria confer multiple health benefits, including preventing the growth, colonization, or carriage of harmful bacteria in the gut. Bacteriocins are antibacterial peptides produced by diverse bacteria, and their production is tightly regulated and coordinated at the transcriptional level. A popular strategy for enhancing the antibacterial properties of probiotic bacteria is to retrofit them with the ability to overproduce heterologous bacteriocins.
View Article and Find Full Text PDFCurr Res Microb Sci
December 2021
Lehrstuhl für Technische Mikrobiologie, Technische Universität München, Germany.
mBio
April 2020
Center for Life Sciences, Skolkovo Institute of Science and Technology, Skolkovo, Russia
The microcin C (McC) and related compounds are potent Trojan horse peptide-nucleotide antibiotics. The peptide part facilitates transport into sensitive cells. Inside the cell, the peptide part is degraded by nonspecific peptidases releasing an aspartamide-adenylate containing a phosphoramide bond.
View Article and Find Full Text PDF