関連する実験動画
Updated: May 10, 2026

11:22
Measuring the Kinetics of mRNA Transcription in Single Living Cells
Published on: August 25, 2011
普遍的な転写停止は,RNAポリメラーゼのバックトラッキングとは無関係です
Keir C Neuman1, Elio A Abbondanzieri, Robert Landick
1Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA.
Cell
|November 19, 2003
まとめ
この研究は,DNA転写中のRNAポリメラーゼ (RNAP) の一時停止が短く,バックトラッキングによって引き起こされないことを明らかにしています. これらの頻繁な休止は,内部酵素の構造的再編成の結果である可能性があり,転写機構に関する新しい洞察を提供します.
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
- 遺伝学 遺伝学とは
背景:
- RNAポリメラーゼ (RNAP) は不連続なDNA転写を示し,それは頻繁な休止と交差した急速な核酸添加によって特徴付けられます.
- RNAPの停止を制御する正確なメカニズムを理解することは,遺伝子発現の調節を理解するために重要です.
研究 の 目的:
- 単一のEscherichia coliのトランスクリプション延長複合体に対する外部の力の影響を測定することによって,トランスクリプションの停止の根本的なメカニズムを調査する.
- バックトラッキングとRNAPの停止の他の潜在的な原因を区別する.
主な方法:
- 単一の転写延長複合体に阻害力と補助力を適用するために,光学トラッピング装置を使用しました.
- RNAPの転位ダイナミクスを測定し,1秒間の一時停止を検出することができました.
主要な成果:
- RNAPの休止の大半は短期間 (21°Cで1秒から6秒,NTPで1mM) であった.
- パウスの確率と持続は,阻害または補助負荷によって影響を受けませんでした.
- これらの発見は,どこにでも存在する一時停止の原因としてバックトラッキングを排除します.
結論:
- RNAPトランスクリプションで観察される至る所に存在する短い一時停止は,バックトラッキングによるものではありません.
- RNAポリメラーゼ酵素内の構造的再編成が,これらの一時停止の主要な原因として提案されています.
関連する概念動画
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...

