相关实验视频

Updated: Aug 15, 2025

Characterizing RNA Modifications in Single Neurons Using Mass Spectrometry

Characterizing RNA Modifications in Single Neurons Using Mass Spectrometry

Published on: April 21, 2022

通过METTL1-WDR4进行tRNA甲基化的结构和机制

Victor M Ruiz-Arroyo^1,2,3, Rishi Raj^1,2,3, Kesavan Babu^1,2,3

¹Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA.

|January 4, 2023

概括

METTL1-WDR4复合体在tRNA上产生7-甲基氨酸 (m7G),这对基因表达至关重要. 结构研究揭示了该复合物如何识别tRNA并激活m7G甲基化,从而提供了对细胞生长和疾病中的作用的见解.

科学领域:

生物化学和分子生物学
结构生物学
表观遗传学

背景情况:

特定的RNA修饰对于调节基因表达和细胞功能至关重要.
转移RNAs (tRNAs) 含有众多化学修饰物,包括位于46位的7-甲基瓜诺辛 (m7G),它影响tRNA稳定性,细胞水平和生长.
负责人类m7G46形成的METTL1- WDR4复合物的失调与发育障碍和癌症有关.

研究的目的:

阐明METTL1-WDR4复合体识别RNA基质并催化m7G甲基化的结构机制.
了解由METTL1-WDR4进行的m7G修改的监管机制.

主要方法:

用X射线结晶学来确定METTL1-WDR4复合物的结构.
低温电子显微镜 (cryo-EM) 以可视化METTL1-WDR4-tRNA复合体在各种状态,包括辅助因子.
酶活性部位和基质相互作用的结构分析.

主要成果:

METTL1-WDR4复合体利用复合蛋白表面通过形状互补性来识别tRNA肘部.
结构快照显示了催化机制,包括辅因子结合和活性位点动态.
METTL1 N端作为一个调节开关,将合因子与激活m7G甲基化所必需的结构变化结合起来.

结论:

该研究提供了详细的结构模型,解释了METTL1-WDR4复合体对m7G修饰的核心和调节机制.
这些发现为了解m7G修饰的生物学作用和疾病影响提供了框架.
对METTL1 N端的翻译后修改的洞察力表明甲基化活动的关键监管点.

更多相关视频

An In Vitro Assay to Detect tRNA-Isopentenyl Transferase Activity

An In Vitro Assay to Detect tRNA-Isopentenyl Transferase Activity

Published on: October 8, 2018

Antibody-Free Assay for RNA Methyltransferase Activity Analysis

Antibody-Free Assay for RNA Methyltransferase Activity Analysis

Published on: July 9, 2019

相关概念视频

Transfer RNA Synthesis

Transfer RNA Synthesis

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...

tRNA Activation

tRNA Activation

Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...

RNA Structure

RNA Structure

The basic structure of RNA consists of a string of ribonucleotides attached by phosphodiester bonds. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation.
Different Types of RNA Have the Same Basic Structure
There are three main types of ribonucleic acid (RNA) involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three...

RNA Stability

RNA Stability

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...

Nucleic Acid Structure

Nucleic Acid Structure

The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′ to 3′ phosphodiester linkage.
DNA Structure
DNA...

RNA Editing

RNA Editing

RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the...