1. The effect of methylation on DNA replication in Salmonella enterica serovar typhimurium
- Author
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Alya El May, Ahmed Landoulsi, Abdelwaheb Chatty, and Amine Aloui
- Subjects
DNA Replication ,DNA, Bacterial ,General Immunology and Microbiology ,DNA replication ,General Medicine ,DNA Methylation ,Salmonella typhi ,Biology ,biology.organism_classification ,Enterobacteriaceae ,General Biochemistry, Genetics and Molecular Biology ,Microbiology ,Transformation (genetics) ,chemistry.chemical_compound ,Plasmid ,chemistry ,Salmonella enterica ,Dam methylase ,DNA methylation ,Transformation, Bacterial ,General Agricultural and Biological Sciences ,DNA ,Plasmids - Abstract
The DNA adenine methylase of Salmonella typhimurium methylates adenine at GATC sequences. Strains deficient in this methylase are not well transformed by methylated plasmids, but unmethylated plasmids transform them at high frequencies. Hemimethylated daughter molecules accumulate after the transformation of dam(-) strains with fully methylated plasmids, suggesting that hemimethylation prevents DNA replication. It will also be shown that plasmids isolated from dam(-) bacteria are hemimethylated by restriction enzyme digestion. These results may explain why newly formed daughter molecules are not substrates for immediate reinitiation of DNA replication in dam(-) bacteria.
- Published
- 2007
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