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A Method for Measuring RNA N6-methyladenosine Modifications in Cells and Tissues

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Published on: December 5, 2016

通过METTL3-METTL14复合物进行N(6) -腺甲基化的结构基础

Xiang Wang¹, Jing Feng¹, Yuan Xue¹

¹National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan 430070, China.

|June 10, 2016

概括

METTL3-METTL14复合物在N(6) - 甲基氨酸 (m(6) A位点上甲基化RNA. 结构和生化数据显示METTL3是催化核,METTL14是m(6) A修饰的RNA结合平台.

科学领域:

生物化学
分子生物学
结构生物学

背景情况:

化学修饰RNA,如N(6) - 甲基氨酸 (m(6) A,对于细胞过程至关重要.
通过RNA甲基转移酶 (MTases) 和脱甲基酶动态调节m(6) A修饰.
甲基转移酶类3 (METTL3) -甲基转移酶类14 (METTL14) 复合体是一个关键的m(6) A甲基转移酶.

研究的目的:

阐明METTL3和METTL14在m(6) A甲基转移酶复合体中的不同作用.
确定METTL3-METTL14复合物的催化活性和基质识别的结构基础.

主要方法:

使用X射线结晶学获得METTL3-METTL14异构体的高分辨率结构.
在无联体,S- 腺甲 (AdoMet) 结合和S- 腺类固醇 (AdoHcy) 结合状态下确定结构.
为了支持结构发现,进行了生物化学分析.

主要成果:

晶体结构显示METTL3和METTL14都具有I类MTase折叠,并通过键相互作用,形成带正电荷的槽.
仅在METTL3活性部位观察到S- 腺甲 (AdoMet),而不是在METTL14.
生物化学数据表明METTL3作为催化成分,而METTL14则作为RNA结合平台.

结论:

METTL3-METTL14复合体具有专门的作用:METTL3是催化核心,METTL14是RNA结合平台.
这种结构和功能洞察力为了解修改及其规范提供了框架.
这些发现突出了类似于DNAN(6) -腺素MTases的目标识别机制.

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