Low-level expression of the Type II restriction-modification system confers potent bacteriophage resistance in Escherichia coli.

ABSTRACT: Restriction-modification systems (R-M) are one of the antiviral defense tools used by bacteria, and those of the Type II family are composed of a restriction endonuclease (REase) and a DNA methyltransferase (MTase). Most entering DNA molecules are usually cleaved by the REase before they can be methylated by MTase, although the observed level of fragmented DNA may vary significantly. Using a model EcoRI R-M system, we report that the balance between DNA methylation and cleavage may be severely affected by transcriptional signals coming from outside the R-M operon. By modulating the activity of the promoter, we obtained a broad range of restriction phenotypes for the EcoRI R-M system that differed by up to 4 orders of magnitude in our biological assays. Surprisingly, we found that high expr

SUBMITTER: Wilkowska K 

PROVIDER: S-EPMC7315355 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature