Pathological phenotypes and in vivo DNA cleavage by unrestrained activity of a phosphorothioate-based restriction system in Salmonella.

ABSTRACT: Prokaryotes protect their genomes from foreign DNA with a diversity of defence mechanisms, including a widespread restriction-modification (R-M) system involving phosphorothioate (PT) modification of the DNA backbone. Unlike classical R-M systems, highly partial PT modification of consensus motifs in bacterial genomes suggests an unusual mechanism of PT-dependent restriction. In Salmonella enterica, PT modification is mediated by four genes dptB-E, while restriction involves additional three genes dptF-H. Here, we performed a series of studies to characterize the PT-dependent restriction, and found that it presented several features distinct with traditional R-M systems. The presence of restriction genes in a PT-deficient mutant was not lethal, but instead resulted in several pathological

SUBMITTER: Cao B 

PROVIDER: S-EPMC4414249 | biostudies-literature | 2014 Aug

REPOSITORIES: biostudies-literature