非酶促序列特异性甲基转移至单链DNA

Iverson B L, Dervan P B

Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena 91125.

Proc Natl Acad Sci U S A. 1988 Jul;85(13):4615-9. doi: 10.1073/pnas.85.13.4615.

2'-Deoxyuridine 5'-triphosphate with a methylthioether moiety at the 5 position can be incorporated into a primer-template DNA complex with Klenow enzyme. Activation with CNBr at 25 degrees C, pH 5.5, followed by treatment with piperidine produces sequence-specific cleavage on the template DNA predominantly at a single guanine position. The mechanism involves methyl-group transfer from sulfur on the modified deoxyuridine of the extended primer to N-7 of guanine on the template DNA. This raises the possibility for the design and synthesis of a nonenzymatic class of sequence-specific methyltransferases for DNA.

5位带有甲硫醚部分的2'-脱氧尿苷5'-三磷酸可以与克列诺酶一起掺入引物-模板DNA复合物中。在25℃、pH 5.5条件下用溴化氰激活，随后用哌啶处理，可使模板DNA主要在单个鸟嘌呤位置发生序列特异性切割。其机制涉及甲基从延伸引物上修饰的脱氧尿苷的硫转移至模板DNA上鸟嘌呤的N-7位。这为设计和合成一类用于DNA的非酶促序列特异性甲基转移酶提供了可能性。