相关实验视频
Updated: Apr 17, 2026

07:44
High-throughput Purification of Affinity-tagged Recombinant Proteins
Published on: August 26, 2012
15.0K
RNA聚合酶II-Mediator核心启动复合物的结构
C Plaschka1, L Larivière2, L Wenzeck2
1Max Planck Institute for Biophysical Chemistry, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany.
Nature
|February 6, 2015
概括
研究人员重建了核心调解器 (cMed) 综合体,并确定其与RNA聚合酶II (Pol II) 结合的结构. 这揭示了Mediator如何与Pol II相互作用,以调节基因转录启动.
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:
- 媒介体复合体是一个关键的联合激活剂,它调节了RNA聚合酶II (Pol II) 的转录启动.
- 了解Mediator的结构和功能对于破译基因表达控制至关重要.
研究的目的:
- 从Saccharomyces cerevisiae中复制一个活跃的15个亚单元核心调解器 (cMed) 复合体.
- 确定cMed与核心转录启动复合体结合的高分辨率冷电子显微镜结构.
主要方法:
- 重建15个子单元核心的中间体综合体.
- 低温电子显微镜 (cryo-EM) 用于在9.7 Å分辨率下确定结构.
- 调解员-Pol II-启动复杂相互作用的结构分析.
主要成果:
- 该结构显示cMed与Rpb4-Rpb7茎和碳氧终端域 (CTD) 附近的Pol II结合.
- 特定的中间体模块 (头部,中部,尾部) 与Pol II和转录因子相互作用,稳定启动复合体.
- Med14子单元作为连接不同介质模块的结构"梁",可能会影响Pol II形状和CTD酸化.
结论:
- 重建的cMed结构为中介者在稳定转录启动复合体中的作用提供了原子层面的见解.
- 这些发现阐明了Mediator如何与Pol II及其相关因子相互作用,以调节转录启动和Pol IICTD酸化.
相关概念视频
Transcription Initiation
22.3K
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...
22.3K
RNA Polymerase II Accessory Proteins
4.3K
4.3K
RNA Polymerase II Accessory Proteins
11.5K
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...
11.5K
General Transcription Factors
7.8K
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...
7.8K
Eukaryotic RNA Polymerases
28.5K
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...
All three eukaryotic RNAPs require specific transcription factors, of which the...
28.5K
Eukaryotic RNA Polymerases
11.2K
11.2K

