A reversion assay system previously implemented to demonstrate the existence of adaptive or stationary-phase-induced mutagenesis in Bacillus subtilis was utilized in this report to study the influence of the mismatch DNA repair (MMR) system on this type of mutagenesis. Results revealed that a strain deficient in MutSL showed a significant propensity to generate increased numbers of stationary-phase-induced revertants. These results suggest that absence or depression of MMR is an important factor in the mutagenesis of nongrowing B. subtilis cells because of the role of MMR in repairing DNA damage. In agreement with this suggestion, a significant decrease in the number of adaptive revertant colonies, for the three markers tested, occurred in B. subtilis cells which overexpressed a component of the MMR system. Interestingly, the single overexpression of mutS, but not of mutL, was sufficient to decrease the level of adaptive mutants in the reversion assay system of B. subtilis. The results presented in this work, as well as in our previous studies, appear to suggest that an MMR deficiency, putatively attributable to inactivation or saturation with DNA damage of MutS, may occur in a subset of B. subtilis cells that differentiate into the hypermutable state.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC516593 | PMC |
http://dx.doi.org/10.1128/JB.186.19.6485-6491.2004 | DOI Listing |
Vet Res Commun
January 2025
Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta N 36 Km 601, Río Cuarto City, 5800, Córdoba, Argentina.
Post-weaning diarrhea (PWD) is a major concern for pig producers, as stress and early weaning increase susceptibility to enteropathogens like enterotoxigenic Escherichia coli (ETEC) and Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium).
View Article and Find Full Text PDFDalton Trans
January 2025
Department of Applied Chemistry, Cochin University of Science and Technology, Kochi 22, Kerala, India.
The rise of various diseases demands the development of new agents with antioxidant, antimicrobial, anti-inflammatory, enzyme-inhibiting, and cytotoxic properties. In this study, heterocyclic Schiff base complexes of Cu(II) featuring a benzo[]thiophene moiety were synthesized and their biological activities evaluated. The complexes were characterized using FT-IR, UV-Vis, and EPR spectroscopy, TG-DTG analysis, magnetic moment measurements, molar conductivity measurements, and elemental analyses.
View Article and Find Full Text PDFNucleic Acids Res
January 2025
EGM CNRS, Université Paris-Cité,Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
Faced with nutritional stress, some bacteria form endospores capable of enduring extreme conditions for long periods of time; yet the function of many proteins expressed during sporulation remains a mystery. We identify one such protein, KapD, as a 3'-exoribonuclease expressed under control of the mother cell-specific transcription factors SigE and SigK in Bacillus subtilis. KapD dynamically assembles over the spore surface through a direct interaction with the major crust protein CotY.
View Article and Find Full Text PDFSci Rep
January 2025
Laboratory of Extremophiles Biology, Department of Microbiology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, Gdansk, 80-308, Poland.
In this study, we evaluated the combined effect between MLE-15, a modular lytic enzyme composed of four building blocks, and reline, a natural deep eutectic solvent. The bioinformatic analysis allowed us to determine the spatial architecture of MLE-15, whose components were bactericidal peptide cecropin A connected via a flexible linker to the cell wall binding domain (CBD) of mesophilic 201ϕ2 - 1 endolysin and catalytic domain (EAD) of highly thermostable Ph2119 endolysin. The modular enzyme showed high thermostability with the melting temperature of 93.
View Article and Find Full Text PDFCurr Microbiol
January 2025
Department of Microbiology and Botany, School of Sciences, J. C. Road, JAIN (Deemed-to-be University), Bangalore, Karnataka, 560027, India.
Endophytic fungi are non-pathogenic organisms that colonise healthy plant tissues asymptomatically. Endophytes derived from medicinal plants are sources for identifying natural products and bioactive compounds with potential uses for industry, medicine, agriculture, and related sectors. In the present study, ethyl acetate crude extracts of four endophytic fungal isolates (CALF1, CALF4, and CASF1) from the medicinal plant Plectranthus amboinicus showed potent antimicrobial activity against the test pathogenic bacteria Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus subtilis using disc diffusion assays.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!