相关实验视频
Updated: Feb 19, 2026

07:44
High-throughput Purification of Affinity-tagged Recombinant Proteins
Published on: August 26, 2012
14.8K
转录前启动复合体与TFIIH和Mediator的结构
S Schilbach1, M Hantsche1, D Tegunov1
1Max Planck Institute for Biophysical Chemistry, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany.
Nature
|November 2, 2017
概括
低温EM结构揭示了转录因子IIH (TFIIH) 和媒介复合体如何组装以启动RNA聚合酶II (Pol II) 的转录. 这些发现揭示了TFIIH
科学领域:
- 分子生物学
- 结构生物学
- 生物化学
背景情况:
- RNA聚合酶II (Pol II) 通过在促进体DNA上形成具有一般转录因子的预启动复合体 (PIC) 来启动转录.
- 了解PIC组合和功能的结构基础对于破译基因调节至关重要.
研究的目的:
- 确定Saccharomyces cerevisiae PIC和PIC核心介质的高分辨率冷电子显微镜 (冷EM) 结构.
- 阐明转录因子IIH (TFIIH) 核和激酶模块在促进体DNA开放和Pol II酸化中的作用.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 来获得PIC和PIC核心介质复合物的结构.
- 对于PIC和PIC核心的Mediator复合体,分别实现了4.7 Å和5.8 Å的名义分辨率.
主要成果:
- 这些结构显示了TFIIH子单元的精确位置,包括Ssl2,在PIC内,与TFIIE刺激的DNA开放相一致.
- TFIIH激酶模块子单元Tfb3定基因酶Kin28 (CDK7),该基因酶是可移动的,但优先位于中介体附近.
- 在Mediator复合体内发现的开放空间表明Kin28可化Pol II的C终端域.
结论:
- 这项研究为Saccharomyces cerevisiae PIC及其核心中介体提供了前所未有的结构洞察力.
- 这些发现澄清了TFIIH模块在促进体DNA解和Pol II C终端域酸化中的功能作用.
- 这项工作使我们对控制真核转录的复杂机制有了进一步的了解.
相关概念视频
General Transcription Factors
7.2K
Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of...
7.2K
Transcription Initiation
21.5K
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...
21.5K
Transcription Factors
83.0K
Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of...
83.0K
RNA Polymerase II Accessory Proteins
11.1K
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...
11.1K
RNA Polymerase II Accessory Proteins
4.1K
4.1K
Transcription Elongation Factors
14.1K
Transcription elongation is a dynamic process that alters depending upon the sequence heterogeneity of the DNA being transcribed. Hence, it is not surprising that the elongation complex's composition also varies along the way while transcribing a gene.
The transcription elongation is regulated via pausing of RNA polymerase on several occasions during transcription. In bacteria, these halts are necessary because the transcription of DNA into mRNA is coupled to the translation of that mRNA...
The transcription elongation is regulated via pausing of RNA polymerase on several occasions during transcription. In bacteria, these halts are necessary because the transcription of DNA into mRNA is coupled to the translation of that mRNA...
14.1K

