转运RNA中1-methyguanosine修饰核苷研究进展

Review on the synthesis and function of 1-methylguanosine on transfer RNAs

tRNA中存在着大量转录后修饰,这些修饰的存在对tRNA的结构和功能有很大影响。截至目前为止,已经发现了至少108种tRNA转录后修饰,其中碱基或核糖的甲基化最为常见。有研究证明,鸟嘌呤第一位N原子甲基化形成1-methyguanosine(m^1G),m^1G修饰对提高tRNA的结构稳定性,诱导tRNA的正确折叠,以及降低翻译中的错误起关键作用。总结目前已知的m^1G修饰在tRNA中的合成位点及作用,比较合成不同位点m^1G修饰的酶的不同结构和生化特性,着重介绍不同的酶和底物tRNA的特异性结合介导m^1G形成背后的分子机制。为m^1G核苷修饰及其相关蛋白的功能研究提供一定的参考价值,希望对后续相关研究提供一定启发。

Many nucleosides in transfer RNAs are modified.Modified nucleosides play important roles in the structure and function of tRNAs.Up to now,more than 108 kinds of modified nucleosides have been identified,and methylation is one of most commonly found post-transcriptional modification on tRNA molecules.Methylation and N1 position of guanosine,or 1-methylguanosine(m^1G),is presented on different tRNAs.Studies have shown that the presence of m^1G at those locations are good for stabilizing tRNA tertiary structure,correct folding and preventing translational error.In this review,we discussed the location and functionality of m^1G,summarized enzymes found for m^1G,and compard their biochemical activity and biological roles in different organisms,with highlight on the mechanism difference on the synthesis and difference on substrate recognition by protein domains for each of the activity.we hope to provide a reference for the study of m^1G nucleoside modification and its related proteins,and to give insight for future research in related area.