関連する実験動画
Updated: Jul 29, 2026

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Measuring the Kinetics of mRNA Transcription in Single Living Cells
Published on: August 25, 2011
RNAポリメラーゼの単一分子の力と速度を測定した
M D Wang1, M J Schnitzer, H Yin
1Department of Molecular Biology and Princeton Materials Institute, Princeton University, Princeton, NJ 08544, USA.
まとめ
RNAポリメラーゼ (RNAP) は,転写中の分子モーターとして機能します. 新しい研究によると,高い力がRNAPを止めることは,単一のベースステップではなく,大きな逆の構造変化を引き起こすことによって可能である.
科学分野:
- 分子生物学は分子生物学である.
- バイオフィジックス 生物物理学
- バイオケミストリー バイオケミストリー
背景:
- RNAポリメラーゼ (RNAP) は,DNAに沿って移動し,転写に不可欠な分子モーターです.
- RNAPの動きを理解することは,そのメカニズムの解読に不可欠です.
研究 の 目的:
- 単一のEscherichia coli RNAP分子の力-速度関係を調査する.
- 外部の力が転写速度とメカニズムにどのように影響するか判断する.
主な方法:
- 精密な力を単一のRNAP分子に適用するために,フィードバック制御された光学トラップを使用しました.
- 適用された力の範囲にわたって測定された転写速度.
主要な成果:
- RNAPの力-速度曲線は,ミオシンやキネシンなどの他のモータータンパク質と異なるユニークな形状を示しています.
- 低力は,直接運動を生成しない生化学的ステップによって制限されます.
- 高い力がRNAPを阻害し,構造的再編成 (5〜10塩基対) を引き起こすように見える.
結論:
- RNAPのモーターメカニズムは,他の確立された分子モーターと異なる.
- 単一段階の転位だけではなく,力によって引き起こされる構造の変化は,負荷下でのRNAP活性を調節する上で重要な役割を果たします.
関連する概念動画
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...

