相关实验视频
Updated: Oct 2, 2026

07:44
High-throughput Purification of Affinity-tagged Recombinant Proteins
Published on: August 26, 2012
细菌RNA聚合酶全酶和RNA聚合酶促进体开放复合物的结构组织
Vladimir Mekler1, Ekaterine Kortkhonjia, Jayanta Mukhopadhyay
1Howard Hughes Medical Institute, Waksman Institute, Rutgers University, Piscataway, NJ 08854, USA.
Cell
|March 15, 2002
概括
研究人员绘制了细菌RNA聚合酶全酶及其促进体开放复合物的3D结构. 密钥西格玛 (Key sigma) 区域1.1发生了显著的变化,揭示了它在DNA结合中的作用.
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:
- 细菌RNA聚合酶全酶对于转录启动至关重要.
- 了解西格玛 (sigma) 相互作用的结构动态是解读转录调节的关键.
研究的目的:
- 确定细菌RNA聚合酶全酶和RNA聚合酶促进体在溶液中的三维结构.
- 阐明sigma的结构基础{70) 与核心酶和DNA的相互作用.
主要方法:
- 使用了系统的光共振能量转移 (FRET).
- 限制距离的对接被用来建模结构.
主要成果:
- 定义了全酶和开放复合体的三维结构.
- 在Sigma ((70) 区域1.2,2,3,和4显示在两个州的类似位置.
- 西格玛(70) 1.1区域表现出显著的位置差异,位于全酶中的活性中心裂中,位于开放复合体的外部.
结论:
- 这项研究为理解西格玛 (sigma) 相互作用提供了一个结构框架.
- 西格玛70区域1.1的独特位置表明它在DNA结合和转录启动中起着调节作用.
- 该方法适用于研究其他大型分子复合体.
相关概念视频
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...
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...
Bacterial Transcription
RNA polymerase (RNAP) carries out DNA-dependent RNA synthesis in both bacteria and eukaryotes. Bacteria do not have a membrane-bound nucleus. So, transcription and translation occur simultaneously, on the same DNA template.
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
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...
All three eukaryotic RNAPs require specific transcription factors, of which the...
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...
All three eukaryotic RNAPs require specific transcription factors, of which the...
Transcription Initiation
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...

