The structures of three recombinants between bacteriophage lambda DNA and plasmid pBR322 that were generated in a recA derivative of Escherichia coli are described. Each resulted from two illegitimate recombination events that resulted in the substitution of part of the lambda genome by part of the plasmid genome. The nucleotide sequences at the six lambda-plasmid junctions were determined and compared with the sequences of the lambda and plasmid genomes before recombination. Each recombination occurred at a short region of homology in the two genomes, and other short regions of homology were found near some of the junctions. The structures of these junctions are similar to those resulting from illegitimate recombination in animal cells. A model to explain how these multiple illegitimate recombination events could result from a cascade of DNA gyrase-catalyzed recombinations is discussed.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC393843 | PMC |
http://dx.doi.org/10.1073/pnas.80.9.2452 | DOI Listing |
Nat Commun
October 2024
Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan.
Homologous recombination during meiosis is critical for chromosome segregation and also gives rise to genetic diversity. Genetic exchange between homologous chromosomes during meiosis is mediated by the recombinase Dmc1, which is capable of recombining DNA sequences with mismatches. The Hop2-Mnd1 complex mediates Dmc1 activity.
View Article and Find Full Text PDFPlasmid
December 2024
Microbial Pharmacology and Population Biology Research Group, Department of Pharmacy, UiT The Arctic University of Norway, Tromsø, Norway. Electronic address:
Plasmids can impact the evolution of their hosts, e.g. due to carriage of mutagenic genes, through cross-talk with host genes or as result of SOS induction during transfer.
View Article and Find Full Text PDFNat Struct Mol Biol
January 2025
Genome Integrity laboratory, Medical Research Council Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
Tumor suppressor p53-binding protein 1 (53BP1) regulates DNA end joining in lymphocytes, diversifying immune antigen receptors. This involves nucleosome-bound 53BP1 at DNA double-stranded breaks (DSBs) recruiting Rap1-interacting factor 1 homolog (RIF1) and shieldin, a poorly understood DNA-binding complex. The 53BP1-RIF1-shieldin axis is pathological in BRCA1-mutated cancers, blocking homologous recombination (HR) and driving illegitimate nonhomologous end joining (NHEJ).
View Article and Find Full Text PDFSci Rep
September 2024
Division of Molecular Biology, Ruđer Bošković Institute, Bijenička 54, 10 000, Zagreb, Croatia.
Single-strand DNA-binding proteins SSB/RPA are ubiquitous and essential proteins that bind ssDNA in bacteria/eukaryotes and coordinate DNA metabolic processes such as replication, repair, and recombination. SSB protects ssDNA from degradation by nucleases, while also facilitating/regulating the activity of multiple partner proteins involved in DNA processes. Using Spi assay, which detects aberrantly excised λ prophage from the E.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
May 2024
Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
Horizontal gene transfer occurs frequently in bacteria, but the mechanism driving activation and optimization of the expression of horizontally transferred genes (HTGs) in new recipient strains is not clear. Our previous study found that spontaneous tandem DNA duplication resulted in rapid activation of HTGs. Here, we took advantage of this finding to develop a novel technique for tandem gene duplication, named tandem gene duplication selected by activation of horizontally transferred gene in bacteria (TDAH), in which tandem duplication was selected by the activation of horizontally transferred selectable marker gene.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!