Bron S, Luxen E, Venema G
Mol Gen Genet. 1984;195(1-2):370-3. doi: 10.1007/BF00332776.
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.
研究了BsuR系统对半甲基化SPP1 DNA的限制作用。在体外，在半甲基化DNA的未修饰链上引入单链切口，其位置与未修饰的同型双链DNA中识别的位点相同。用BsuR处理的半甲基化DNA转染效率严重降低。在体内，在枯草芽孢杆菌R感受态细胞中，用半甲基化DNA转染效率也严重降低。相比之下，用这种DNA转染R菌株的原生质体不受影响。感受态细胞的明显限制作用归因于转染DNA的特殊加工方式。
