具有m6A核酸的METTL3-METTL14的结构揭示了对m6A转化和传感的洞察力
Shan Qi1,2, Abhay Kumar1,2, Shuang Chen3
1Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, 8403 Floyd Curl Drive, San Antonio, TX 78229, USA.
Research square
|August 23, 2023
概括
酶复合体METTL3-METTL14在RNA上产生m6A标记. 一个新的结构揭示了这种甲基化是如何感知,提供了关于影响RNA调节的癌症相关突变的见解.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
背景情况:
- METTL3-METTL14复合物催化了RNA上的N1-甲基氨酸 (m6A) 标记的形成,这些标记对于调节RNA稳定性和功能至关重要.
- 虽然METTL3也可以作为m6A阅读器,但m6A写入,阅读和感知的精确机制仍然不完全理解.
研究的目的:
- 阐明由METTL3-METTL14复合体编写和感知m6A的结构基础.
- 研究癌症相关突变对METTL3-METTL14活性和RNA结合的功能后果.
主要方法:
- 使用X射线晶体学来确定人类METTL3-METTL14甲基转移酶核心的结构.
- 结构被确定为复杂的N1-甲基氨酸单酸盐 (m6A),反应产品的模仿.
- 对癌症相关突变的分析,以评估它们对RNA结合和甲基化动态的影响.
主要成果:
- 获得了METTL3-METTL14复杂后催化物的高分辨率结构 (~2.5 Å).
- m6A产品与与S-adenosylmethionine (SAM) 结合部位不同的RNA结合口袋结合,该结合部位位于约16 Å的距离.
- 提出了一种两步模型,涉及腺的"旋转"和随后的"感知"RNA结合口袋的甲基化状态.
- 发现与癌症相关的突变会损害RNA结合,脱和m6A写入/传感功能.
结论:
- 这项研究揭示了通过METTL3-METTL14中的专门RNA结合口袋来感知m6A的新奇机制.
- 这个口袋在调节酶从写字器切换到传感器方面发挥着至关重要的作用.
- 了解这些机制和突变的影响对于破译RNA表观遗传调节在健康和疾病,特别是癌症中至关重要.
相关概念视频
Riboswitches
8.2K
Riboswitches are non-coding mRNA domains that regulate the transcription and translation of downstream genes without the help of proteins. Riboswitches bind directly to a metabolite and can form unique stem-loop or hairpin structures in response to the amount of the metabolite present. They have two distinct regions – a metabolite-binding aptamer and an expression platform.
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
8.2K
Transfer RNA Synthesis
12.0K
One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases.
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
12.0K
Covalently Linked Protein Regulators
6.9K
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein....
These groups modify specific amino acids in a protein....
6.9K
Translational Regulation
44
Translational regulation in prokaryotes ensures efficient protein synthesis by controlling ribosome access to mRNA. This regulation is mediated by secondary RNA structures, including translational riboswitches, RNA thermometers, and small RNAs (sRNAs), which respond to intracellular and environmental signals to modulate gene expression.Translational RiboswitchesRiboswitches in the leader region of mRNAs can regulate translation by altering the accessibility of the Shine-Dalgarno (SD) sequence,...
44
RNA Stability
33.6K
Intact DNA strands can be found in fossils, while scientists sometimes struggle to keep RNA intact under laboratory conditions. The structural variations between RNA and DNA underlie the differences in their stability and longevity. Because DNA is double-stranded, it is inherently more stable. The single-stranded structure of RNA is less stable but also more flexible and can form weak internal bonds. Additionally, most RNAs in the cell are relatively short, while DNA can be up to 250 million...
33.6K


