相关实验视频
Updated: Jul 29, 2026

11:22
Measuring the Kinetics of mRNA Transcription in Single Living Cells
Published on: August 25, 2011
对单个RNA聚合酶分子测量的力和速度
M D Wang1, M J Schnitzer, H Yin
1Department of Molecular Biology and Princeton Materials Institute, Princeton University, Princeton, NJ 08544, USA.
概括
RNA聚合酶 (RNAP) 在转录过程中起到分子电机的作用. 新的研究表明,高强度可能会通过引起巨大的逆向结构变化来阻止RNAP,而不仅仅是单基步骤.
科学领域:
- 分子生物学分子生物学
- 生物物理学的生物物理.
- 生物化学 生物化学
背景情况:
- RNA聚合酶 (RNAP) 是转录必不可少的分子电机,沿着DNA移动.
- 了解RNAP在强力下的运动对于破译其机制至关重要.
研究的目的:
- 为了研究单个大肠杆菌RNAP分子的力-速度关系.
- 确定外部力量如何影响转录速度和机制.
主要方法:
- 利用反控制的光学陷,对单个RNAP分子施加精确的力.
- 测量了跨应用力范围的转录速度.
主要成果:
- RNAP的力-速度曲线呈现出独特的形状,与其他运动蛋白质 (如肌和肌) 截然不同.
- 低力受到生化步骤的限制,这些步骤不会直接产生运动.
- 高强力似乎通过诱导显著的逆向结构重组 (5-10个基对) 来阻止RNAP.
结论:
- RNAP的运动机制不同于其他已建立的分子电机.
- 强力诱导的结构变化,而不仅仅是单步转位,在调节负载下RNAP活动方面发挥着关键作用.
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...
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...
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...
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...
All three eukaryotic RNAPs require specific transcription factors, of which the...

