Unique 2′-O-Methylation by Hen1 in Eukaryotic RNA Interference and Bacterial RNA Repair
Unique 2′-O-Methylation by Hen1 in Eukaryotic RNA Interference and Bacterial RNA Repair
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DOI：
10.1021/bi300497x
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发表时间：
2012-05-22
期刊：
影响因子：
2.9
通讯作者：
Huang, Raven H.
中科院分区：
文献类型：
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作者：
Huang, Raven H.
在RNA转录物中，3 '末端核苷酸处的2'-OH基团是独特的，因为它是唯一与3 '-OH基团而不是磷酸骨架相邻的2'-OH基团。某些RNA的3 '端核苷酸的2'-OH基团在体内被甲基化，这是由一种名为Hen 1的甲基转移酶实现的，该甲基转移酶在机制上不同于其他已知的RNA 2 '-O-甲基转移酶。在真核生物中，小RNA的3 '-末端2'-O-甲基化使这些小RNA稳定以用于RNA干扰（RNAi）。在细菌中，RNA修复过程中的相同甲基化导致修复的RNA在修复位点抵抗未来的损伤。虽然真核生物和细菌Hen 1所进行的化学反应是相同的，但真核生物RNAi和细菌RNA修复之间如何通过3 '-末端2'-O-甲基化来稳定RNA的机制是不同的。本文主要介绍了Hen 1在生物体内的分布、Hen 1的四个亚家族、Hen 1的结构和作用机制，以及Hen 1在细菌和真核生物中的可能进化起源。
In an RNA transcript, the 2'-OH group at the 3'-terminal nucleotide is unique as it is the only 2'-OH group that is adjacent to a 3'-OH group instead of a phosphate backbone. The 2'-OH group at the 3'-terminal nucleotide of certain RNAs is methylated in vivo, which is acheived by a methyltransferase named Hen1 that is mechanistically distinct from other known RNA 2'-O-methyltransferases. In eukaryotic organisms, 3'-terminal 2'-O-methylation of small RNAs stabilizes these small RNAs for RNA interference (RNAi). In bacteria, the same methylation during RNA repair results in repaired RNA resisting future damage at the site of repair. Although the chemistry performed by the eukaryotic and bacterial Hen1 is the same, the mechanisms of how RNA is stabilized as a result of the 3'-terminal 2'-O-methylation are different between the eukaryotic RNAi and the bacterial RNA repair. In this review, I will discuss the distribution of Hen1 in living organisms, the classification of Hen1 into four subfamilies, the structure and mechanism of Hen1 that allows it to conduct RNA 3'-terminal 2'-O-methylation, and the possible evolutionary origin of Hen1 present in bacterial and eukaryotic organisms.