関連する実験動画
Updated: Jul 20, 2026

07:44
High-throughput Purification of Affinity-tagged Recombinant Proteins
Published on: August 26, 2012
E. coli RNAポリメラーゼのバイナリ,イニシアーション,トリナリ複合体の展開角度分析に基づく転写のためのトポロジカルモデル
Cell
|May 1, 1982
まとめ
Escherichia coliのRNAポリメラーゼはDNAを17塩基対で解き放ち,これは転写中の常数である. これは,酵素活動,アンワンドーゼとリワンドーゼが,DNAヘリックス通過とRNAトランスクリプトの移動を促進することを示唆しています.
科学分野:
- 分子生物学は分子生物学である.
- バイオケミストリー バイオケミストリー
- 遺伝学 遺伝学とは
背景:
- DNAの解き放たれは,転写の開始と延長における重要なステップです.
- RNAポリメラーゼによるDNAヘリックス操作の正確なメカニズムはまだ調査中です.
研究 の 目的:
- Escherichia coli RNAポリメラーゼによるDNA解離を定量化するために.
- トランスクリプションの開始と延長におけるDNA解の役割を明らかにする.
- DNAに沿ったRNAポリメラーゼの動きのモデルを提案する.
主な方法:
- バイナリ,イニシエーション,および三重複合体のDNA解角の測定.
- 類人猿のウイルス40DNAに独特のプロモーター配列を使用しています.
- トランスクリプションアッセイは37°Cで測定されます.
主要な成果:
- すべての複合体は17 ± 1塩基対 (580° ± 30°) の一貫したDNA解き角を示した.
- DNAの解き放たれは酵素によって安定させられ,転写を通して維持されます.
- 延伸の過程で回転角の異質性は観察されなかった.
結論:
- DNA穿越のためのRNAポリメラーゼ内で"アンウィンドーゼ"と"リウィンドーゼ"の活動が存在することを提案する.
- UnwindaseがDNAを解き放ち,RewindaseがRNAを移動させ,ヘリクスを再密封するモデルを提案します.
- ポリメラーゼの停止と終了のためのメカニズムとしてRNA-DNAハイブリッド形成を仮説化する.
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...
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...
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...
Transcription in Prokaryotes
Transcription is a highly regulated process that converts genetic information into RNA molecules. The transcription cycle is divided into three key stages: initiation, elongation, and termination, each driven by specific molecular mechanisms.Initiation of TranscriptionIn bacteria, transcription begins when the RNA polymerase core enzyme associates with a sigma factor to form a holoenzyme. For example, the E. coli sigma factor called σ70 forms a holoenzyme, which recognizes the -10 (Pribnow box)...

