作为宏分子转录处理复合体的组装护理器的tRNA
Julia Bartuli1, Stefan Jungwirth1, Manisha Dixit1,2
1Department of Biochemistry 1, Theodor Boveri-Institute, University of Würzburg, Würzburg, Germany.
Nature structural & molecular biology
|September 4, 2025
概括
转移RNAs (tRNAs) 在天花病毒感染期间充当组装护士,促进病毒RNA聚合酶复合体的形成. 这种新功能涉及特定的,未经修改的tRNAGln/Arg封存和病毒转录因子的招募.
科学领域:
- 分子生物学
- 病毒学
- 结构生物学
背景情况:
- 转移RNAs (tRNAs) 主要以它们在蛋白质翻译中的重要作用而闻名.
- 像Mopox病毒这样的小鼠病毒编码自己的RNA聚合酶 (vRNAP) 来进行复制.
- 病毒宏分子复合体的精确组装机制尚未完全理解.
研究的目的:
- 为了研究tRNA的新功能.
- 阐明特定tRNAs在病毒性RNA聚合酶 (vRNAP) 的组合中的作用.
- 了解tRNA调节病毒转录复合体形成的结构机制.
主要方法:
- 低温电子显微镜 (Cryo-EM) 用于可视化组装中间体.
- 用于研究tRNA封存和因子招募的生物化学测试.
- 对tRNA结构和修饰模式的分析.
主要成果:
- 已识别的tRNAGln/Arg缺乏特定的修饰,作为病毒vRNAP的组合伴侣.
- 证明这种修改后的tRNA可以调节转录和mRNA处理因子的产生.
- 揭示了一种诱导适合机制,涉及抗基G36内部化,形成非正规的tRNA结构.
- 显示这种机制控制了过渡到预启动复合体.
结论:
- 转移RNAs (tRNAs) 在病毒复制中具有以前未被识别的辅助功能.
- 特定的tRNAGln/Arg的封存和结构适应对于病毒性vRNAP的组合和功能至关重要.
- 这种tRNA介导的组装机制保留在致病性Mpox病毒中,突出显示了其生物学意义.
相关概念视频
Transfer RNA Synthesis
12.2K
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...
12.2K
Transcription Attenuation in Prokaryotes
16.0K
Transcriptional attenuation occurs when RNA transcription is prematurely terminated due to the formation of a terminator mRNA hairpin structure. Bacteria use these hairpins to regulate the transcription process and control the synthesis of several amino acids including histidine, lysine, threonine, and phenylalanine. Transcription attenuation takes place in the non-coding regions of mRNA.
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
16.0K
RNA Polymerase II Accessory Proteins
9.4K
Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...
9.4K
Protein Translocation Machinery on the ER Membrane
4.9K
The translocon complex situated on the ER membrane is the main gateway for the protein secretory pathway. It facilitates the transport of nascent peptides into the ER lumen and their insertion into the ER membrane.
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the...
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the...
4.9K
Protein Complex Assembly
2.1K
2.1K
ATP and Macromolecule Synthesis
6.1K
Biological macromolecules are organic compounds, predominantly composed of carbon atoms. The carbon atoms are covalently bonded with hydrogen, oxygen, nitrogen, and other minor elements. There are four major biological macromolecule classes: carbohydrates, lipids, proteins, and nucleic acids.
Most macromolecules are composed of single subunits, or building blocks, called monomers. The monomers combine with each other using covalent bonds to form larger molecules known as polymers.
Conversion of...
Most macromolecules are composed of single subunits, or building blocks, called monomers. The monomers combine with each other using covalent bonds to form larger molecules known as polymers.
Conversion of...
6.1K


