结合体U4 snRNP核心域的结构及其对snRNP生物发生的影响
Adelaine K W Leung1, Kiyoshi Nagai, Jade Li
1MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK.
Nature
|April 26, 2011
概括
这是spliceosome的组成部分.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 生物化学 生物化学
背景情况:
- 拼接体是RNA拼接的关键分子机器.
- 七个Sm蛋白形成了U1,U2,U4和U5小核核核糖核蛋白 (snRNP) 的核心.
- 在细胞质中将Sm蛋白组合到snRNA上,对于snRNP生物发生是必不可少的.
研究的目的:
- 为了确定U4 snRNP核心域的晶体结构.
- 为了阐明Sm位点RNA与heptamericSm蛋白环之间的相互作用.
- 将U4 snRNP结构与U1 snRNP进行比较,以了解snRNP成熟.
主要方法:
- 在3.6 Å分辨率的X射线晶体学以确定U4 snRNP核心域结构.
- 与现有的U1 snRNP数据 (5.5 Å分辨率) 的结构比较.
主要成果:
- 在 Sm 位点 RNA (AUUUUUG) 和 heptameric Sm 蛋白环 (SmE-SmG-SmD3-SmB-SmD1-SmD2-SmF) 之间详细的原子相互作用.
- 结合涉及不规则的RNA骨干结构和不对称的蛋白质环结构.
- 与U1 snRNP进行比较时,观察到Sm折叠外的snRNA依赖的结构变化.
结论:
- 该结构揭示了核心snRNP组装的精确分子机制.
- 了解这些相互作用提供了对结合体组装和功能的见解.
- 结构变异可能解释在snRNP成熟过程中粒子特异性蛋白质的差异性结合.
相关概念视频
RNA Splicing
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...
RNA Splicing
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...
Ribosomal RNA Synthesis
Ribosome synthesis is a highly complex and coordinated process involving more than 200 assembly factors. The synthesis and processing of ribosomal components occurs not only in the nucleolus but also in the nucleoplasm and the cytoplasm of eukaryotic cells.
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
Additional Subnuclear Structures
The eukaryotic nucleus is a double membrane-bound organelle that contains nearly all of the cell’s genetic material in the form of chromosomes. It is rightly called the “brain” of the cell as it shoulders the responsibility of responding to various physiological processes, stress, altered metabolic conditions, and other cellular signals.
The nucleus contains many membrane-less subnuclear organelles or nuclear bodies, such as nucleoli, Cajal bodies, speckles, paraspeckles, etc. These nuclear...
The nucleus contains many membrane-less subnuclear organelles or nuclear bodies, such as nucleoli, Cajal bodies, speckles, paraspeckles, etc. These nuclear...
Chromatin Structure and RNA Splicing
In eukaryotic cells, nascent mRNA transcripts need to undergo many post-transcriptional modifications to reach the cell cytoplasm and translate into functional proteins. For a long time, transcription and pre-mRNA processing were considered two independent events that occur sequentially in the cell. However, it has now been well established that transcription and pre-mRNA processing are two simultaneous processes that are precisely regulated inside the cell.
The chromatin structure, especially...
The chromatin structure, especially...
Ribosomal RNA Synthesis
Ribosome synthesis is a highly complex and coordinated process involving more than 200 assembly factors. The synthesis and processing of ribosomal components occurs not only in the nucleolus but also in the nucleoplasm and the cytoplasm of eukaryotic cells.
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...


