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大肠杆菌RNase E催化域的结构和对RNA周转的影响
Anastasia J Callaghan1, Maria Jose Marcaida, Jonathan A Stead
1Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK.
Nature
|October 21, 2005
概括
在大肠杆菌中必不可少的酶RNase E通过降解信使RNA来调节基因表达. 它的结构揭示了RNA 5'末端如何控制其活动以及与DNA核酶的进化联系.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 结构生物学 结构生物学
背景情况:
- 协调基因表达对于细胞功能如恒温和发育至关重要.
- 通过有针对性的转录破坏,信使RNA的稳定性会影响代谢途径.
- RNase E 是大肠杆菌中一个关键的内啡核酶,控制RNA的循环和加工.
研究的目的:
- 阐明RNase E的催化活性和基质识别的结构基础.
- 了解RNA的5'终端如何影响RNase E的功能.
- 探索RNA和DNA核酶之间的进化关系.
主要方法:
- 用RNA基质对RNase E的催化域进行X射线晶体学.
- 分析四分体结构和活性部位的形状.
- 使用脱氧核酶进行比较结构分析.
主要成果:
- 获得了RNase E催化域的晶体结构,这些晶体结构被捕获为与RNA的质中间体.
- 确定了由四个RNase E催化子单元组成的四元结构,对活动至关重要.
- 活性部位子域与脱氧核糖核酶具有结构上的相似性,这表明存在进化联系.
- 提出了一种5'-终端RNA识别触发催化作用的机制.
结论:
- RNase E 的四级结构对其催化功能至关重要.
- RNase E的结构揭示了与DNA分裂酶的进化联系.
- 这些发现解释了5'RNA末端识别如何调节RNase E活性和选择性RNA处理.
相关概念视频
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Bacterial RNA Polymerase
Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity.
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Eukaryotic RNA Polymerases
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Initiation is the first step of transcription in eukaryotes. Prokaryotic RNA Polymerase (RNAP) can bind to the template DNA and start transcribing. On the other hand, transcription in eukaryotes requires additional proteins, called transcription factors, to first bind to the promoter region in the DNA template. This binding helps recruit the specific RNAP that can assemble on the DNA and start transcription.
The promoters and enhancers and their accessory proteins allow tight regulation of...
The promoters and enhancers and their accessory proteins allow tight regulation of...
Bacterial RNA Polymerase
Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity.
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
Eukaryotic RNA Polymerases
RNA Polymerase (RNAP) is conserved in all animals, with bacterial, archaeal, and eukaryotic RNAPs sharing significant sequence, structural, and functional similarities. Among the three eukaryotic RNAPs, RNA Polymerase II is most similar to bacterial RNAP in terms of both structural organization and folding topologies of the enzyme subunits. However, these similarities are not reflected in their mechanism of action.
All three eukaryotic RNAPs require specific transcription factors, of which the...
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