In Escherichia coli, a relatively low frequency of recombination exchanges (FRE) is predetermined by the activity of RecA protein, as modulated by a complex regulatory program involving both autoregulation and other factors. The RecA protein of Pseudomonas aeruginosa (RecA(Pa)) exhibits a more robust recombinase activity than its E. coli counterpart (RecA(Ec)). Low-level expression of RecA(Pa) in E. coli cells results in hyperrecombination (an increase of FRE) even in the presence of RecA(Ec). This genetic effect is supported by the biochemical finding that the RecA(Pa) protein is more efficient in filament formation than RecA K72R, a mutant protein with RecA(Ec)-like DNA-binding ability. Expression of RecA(Pa) also partially suppresses the effects of recF, recO, and recR mutations. In concordance with the latter, RecA(Pa) filaments initiate recombination equally from both the 5' and 3' ends. Besides, these filaments exhibit more resistance to disassembly from the 5' ends that makes the ends potentially appropriate for initiation of strand exchange. These comparative genetic and biochemical characteristics reveal that multiple levels are used by bacteria for a programmed regulation of their recombination activities.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1540092 | PMC |
| http://dx.doi.org/10.1128/JB.00358-06 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Extensive homologous recombination safeguards oocyte genome integrity in mammals.
Nucleic Acids Res
January 2025
MOE Key Laboratory of Biosystems Homeostasis and Protection, College of Life Sciences, Zhejiang University, No.866 Yuhangtang Road, 310058, Hangzhou, China.
Meiosis in mammalian oocytes is interrupted by a prolonged arrest at the germinal vesicle stage, during which oocytes have to repair DNA lesions to ensure genome integrity or otherwise undergo apoptosis. The FIRRM/FLIP-FIGNL1 complex dissociates RAD51 from the joint DNA molecules in both homologous recombination (HR) and DNA replication. However, as a type of non-meiotic, non-replicative cells, whether this RAD51-dismantling mechanism regulates genome integrity in oocytes remains elusive.
View Article and Find Full Text PDFThe SOS Response Activation and the Risk of Antibiotic Resistance Enhancement in spp. Strains Exposed to Subinhibitory Concentrations of Ciprofloxacin.
Int J Mol Sci
December 2024
Department of Biology of Bacteria, Institute of Microbiology, Biotechnology and Immunology, Faculty of Biology and Environmental Protection, University of Lodz, 90-237 Lodz, Poland.
The widespread and inappropriate use of antibiotics, for therapeutic and prophylactic purposes, has contributed to a global crisis of rapidly increasing antimicrobial resistance of microorganisms. This resistance is often associated with elevated mutagenesis induced by the presence of antibiotics. Additionally, subinhibitory concentrations of antibiotics can trigger stress responses in bacteria, further exacerbating this problem.
View Article and Find Full Text PDFSRPKs Homolog Dsk1 Regulates Homologous Recombination Repair in Schizosaccharomyces pombe.
Genes Cells
January 2025
Jiangsu Key Laboratory for Pathogens and Ecosystems, College of Life Sciences, Nanjing Normal University, Nanjing, China.
Serine-arginine protein kinases (SRPKs) play important roles in diverse biological processes such as alternative splicing and cell cycle. However, the functions of SRPKs in DNA damage response remain unclear. Here we characterized the function of SRPKs homolog Dsk1 in regulating DNA repair in the fission yeast Schizosaccharomyces pombe.
View Article and Find Full Text PDFRepeated ionizing radiation exposure induces TRIP13 expression, conferring radioresistance in lung cancer cells.
Sci Rep
January 2025
Reproductive Biology Laboratory, Centre for Reproductive Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, 1105AZ, The Netherlands.
Radiation therapy is a common treatment modality for lung cancer, and resistance to radiation can significantly affect treatment outcomes. We recently described that lung cancer cells that express more germ cell cancer genes (GC genes, genes that are usually restricted to the germ line) can repair DNA double-strand breaks more rapidly, show higher rates of proliferation and are more resistant to ionizing radiation than cells that express fewer GC genes. The gene encoding TRIP13 appeared to play a large role in this malignant phenotype.
View Article and Find Full Text PDFDistribution of bacterial DNA repair proteins and their co-occurrence with immune systems.
Cell Rep
January 2025
Laboratory of Biochemistry, Wageningen University, 6708 WE Wageningen, the Netherlands. Electronic address:
Article Synopsis
- Bacteria have various DNA repair mechanisms to keep their genomes intact, but identifying these proteins is tricky due to their similarities.
- A new search strategy helps identify and analyze DNA repair proteins, particularly those involved in RecA-dependent homologous recombination, revealing common proteins like RecA and SSB across many species.
- The study finds that some DNA repair proteins are often found alongside immune system components, suggesting a potential link, but no immune system is entirely dependent on a single DNA repair protein, indicating a complex relationship between these systems in bacteria.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!