Lindsay H, Adams R L
Institute of Biomedical and Life Sciences, University of Glasgow, U.K.
Biochem J. 1996 Dec 1;320 ( Pt 2)(Pt 2):473-8. doi: 10.1042/bj3200473.
Mouse DNA methyltransferase is able to catalyse the transfer of a methyl group to certain CG-containing single-stranded oligonucleotides. The presence of a methylcytosine is required for efficient transfer. This methylcytosine may or may not be on the same oligonucleotide as that containing the accepting CG dinucleotide. When the accepting CG dinucleotide forms part of an unmethylated CG dinucleotide pair, its accepting activity is dramatically reduced. This provides the potential for methylation to spread along the DNA when it is rendered single-stranded at replication. It could also help to maintain fully methylated CG islands and asymmetrically methylated sites.
小鼠DNA甲基转移酶能够催化将甲基基团转移至某些含CG的单链寡核苷酸上。高效转移需要甲基胞嘧啶的存在。这种甲基胞嘧啶可能与含有接受性CG二核苷酸的寡核苷酸在同一条上，也可能不在同一条上。当接受性CG二核苷酸是未甲基化CG二核苷酸对的一部分时，其接受活性会显著降低。这为甲基化在复制时DNA呈单链状态时沿DNA扩散提供了可能性。它也有助于维持完全甲基化的CG岛和不对称甲基化位点。
