Methylation of tRNAAsP by the DNA methyltransferase homolog Dnmt2
Methylation of tRNAAsP by the DNA methyltransferase homolog Dnmt2
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DOI：
10.1126/science.1120976
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发表时间：
2006-01-20
期刊：
影响因子：
56.9
通讯作者：
Bestor, TH
中科院分区：
文献类型：
--
作者：
Goll, MG;Kirpekar, F;Bestor, TH
DNA甲基转移酶-2（DNMT2）的序列和结构与正宗的DNA胞质甲基转移酶具有紧密的亲和力。一种遗传和生化方法的结合表明，人DNMT2不是甲基甲基DNA，而是甲基化的小RNA。质谱法表明该RNA是天冬酸转移RNA（tRNA（ASP）），而DNMT2在反密码子环中特异性甲基化的胞嘧啶38。 DNMT2的功能是高度保守的，人DNMT2蛋白在体外恢复了甲基化，从DNMT2缺乏小鼠，拟南芥和果蝇的毒素菌株中恢复了tRNA（ASP）（ASP），其方式依赖于改良核苷的定位模式的方式。间接序列识别也是真核DNA甲基转移酶的特征，这可能是由DNMT2样RNA甲基转移酶产生的。
The sequence and the structure of DNA methyltransferase-2 (Dnmt2) bear close affinities to authentic DNA cytosine methyltransferases. A combined genetic and biochemical approach revealed that human DNMT2 did not methylate DNA but instead methylated a small RNA; mass spectrometry showed that this RNA is aspartic acid transfer RNA (tRNA(Asp)) and that DNMT2 specifically methylated cytosine 38 in the anticodon loop. The function of DNMT2 is highly conserved, and human DNMT2 protein restored methylation in vitro to tRNA(Asp) from Dnmt2-deficient strains of mouse, Arabidopsis thaliana, and Drosophila melanogaster in a manner that was dependent on preexisting patterns of modified nucleosides. indirect sequence recognition is also a feature of eukaryotic DNA methyltransferases, which may have arisen from a Dnmt2-like RNA methyltransferase.