相关实验视频
Updated: May 10, 2026

11:22
Measuring the Kinetics of mRNA Transcription in Single Living Cells
Published on: August 25, 2011
无处不在的转录暂停是独立于RNA聚合酶回溯的
Keir C Neuman1, Elio A Abbondanzieri, Robert Landick
1Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA.
Cell
|November 19, 2003
概括
这项研究揭示了RNA聚合酶 (RNAP) 在DNA转录过程中的暂停是短暂的,而不是由回溯引起的. 这些频繁的暂停可能是由于内部酶的结构重组造成的,为转录机制提供了新的见解.
科学领域:
- 分子生物学分子生物学
- 生物物理学的生物物理.
- 遗传学 是一个遗传学.
背景情况:
- RNA聚合酶 (RNAP) 呈现不连续的DNA转录,其特征是快速的核酸添加,间隔有频繁的暂停.
- 了解控制RNAP暂停的精确机制对于理解基因表达调节至关重要.
研究的目的:
- 通过测量外部力量对单个 Escherichia coli 转录延长复合物的影响来研究转录暂停的潜在机制.
- 要区分逆行和RNAP暂停的其他潜在原因.
主要方法:
- 使用光学捕捉装置,对单个转录延长复合体施加阻碍和辅助力.
- 测量了RNAP的转位动态,允许检测短短一秒的暂停.
主要成果:
- 大多数RNAP暂停都是短暂的 (在21°C下1-6秒,1毫米NTP).
- 暂停的概率和持续时间不受阻碍或辅助负载的影响.
- 这些发现排除了回溯作为无处不在停顿的原因.
结论:
- 在RNAP转录中观察到的无处不在,短暂的暂停并不是由于回溯.
- 建议RNA聚合酶内的结构重组是这些暂停的主要原因.
相关概念视频
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 Elongation Factors
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 into a...
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 into a...
Transcription Attenuation in Prokaryotes
Transcriptional attenuation occurs when RNA transcription is prematurely terminated due to the formation of a terminator mRNA hairpin structure. Bacteria use these hairpins to regulate the transcription process and control the synthesis of several amino acids including histidine, lysine, threonine, and phenylalanine. Transcription attenuation takes place in the non-coding regions of mRNA.
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
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:
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...
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...

