関連する実験動画
Updated: Jul 15, 2026

07:44
High-throughput Purification of Affinity-tagged Recombinant Proteins
Published on: August 26, 2012
CAPは,プロモーターDNAがない場合,溶液中のRNAポリメラーゼと相互作用する
T Heyduk1, J C Lee, Y W Ebright
1Department of Human Biological Chemistry and Genetics, University of Texas Medical Branch, Galveston 77550.
Nature
|August 5, 1993
まとめ
カタボライト遺伝子アクティベータータンパク質 (CAP) は,RNAポリメラーゼと直接相互作用する. この相互作用は,この能力が欠けている特定のCAP変異体によって示されているように,転写活性化に極めて重要です.
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:
- タンパク質とタンパク質の相互作用は,転写の活性化に不可欠です.
- カタボライト遺伝子アクティベータータンパク質 (CAP) とRNAポリメラーゼの相互作用は提案されているが,直接実証されていない.
- 転写活性化に欠陥がある特定のCAP変異体は,表面ループ (アミノ酸152-166) にマッピングされます.
研究 の 目的:
- 溶液中のCAPとRNAポリメラーゼの間の直接的な相互作用を調査する.
- 転写活性化欠陥CAP変異体がRNAポリメラーゼと相互作用する能力を保持しているかどうかを判断する.
主な方法:
- 熱力学的に厳格な技術である光極化を使用した.
- 野生型のCAPとRNAポリメラーゼの間の結合親和度 (KD,app) を測定した.
- 特定の転写活性化欠陥変異体[Ala158]CAP.の結合を評価した.
主要な成果:
- 野生型のCAPと溶液中のRNAポリメラーゼの間の直接的な相互作用が実証されました (KD,app = 2.8 x 10(-7) M).
- [Ala158]CAPは,特異的に転写活性化に欠陥がある変異体であり,RNAポリメラーゼと相互作用することができなかった.
- これは,トランスクリプションの活性化におけるCAPの機能に相互作用が不可欠であることを示唆しています.
結論:
- CAPとRNAポリメラーゼの間の直接的な物理的相互作用は,転写活性化に不可欠である.
- CAPの表面回路 (アミノ酸152-166) は,この相互作用およびその後の転写調節に不可欠です.
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...
RNA Polymerase II Accessory Proteins
Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...
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...
RNA Polymerase II Accessory Proteins
Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...

