title: Restriction of hemimethylated DNA by the Bacillus subtilis R system.
abstract: The effects of restriction by the BsuR system on hemimethylated SPP1 DNA were investigated. In vitro, single-stranded nicks were introduced in the nonmodified strand of the hemimethylated DNA at the same sites as recognized in nonmodified homoduplex DNA. Transfection with BsuR-treated hemimethylated DNA was severely reduced. In vivo, transfection with hemimethylated DNA was also severely reduced in competent B. subtilis R cells. In contrast, transfection of protoplasts of the R strain with this DNA was not affected. The apparent restriction by competent cells was attributed to the special mode of processing of transfecting DNA.
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics*; D001426:Bacterial Proteins; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics*; D015257:DNA-Cytosine Methylases; D007700:Kinetics; D008745:Methylation; D008780:Methyltransferases / Q000378:metabolism*; D012808:Sigma Factor; D013379:Substrate Specificity; D014157:Transcription Factors; D014162:Transfection
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D012808:Sigma Factor; D014157:Transcription Factors; C092468:spoIIR protein, Bacillus subtilis; C030069:spore-specific proteins, Bacillus; C028464:DNA modification methylase BsuR; D015257:DNA-Cytosine Methylases; D008780:Methyltransferases