関連する実験動画
Updated: Dec 28, 2025

06:48
CD Spectroscopy to Study DNA-Protein Interactions
Published on: February 10, 2022
7.5K
電子と陽子の転送 転写調節器によるDNA結合を調節する RsrR
Jason C Crack1, Patricia Amara2, Anne Volbeda2
1Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U.K.
Journal of the American Chemical Society
|February 21, 2020
まとめ
バクテリア [Fe2S2]-RsrRタンパク質
科学分野:
- 分子生物学
- 生物化学
- 構造生物学
背景:
- [Fe2S2]-RsrRタンパク質は,細胞のリドックス状態に基づいて細菌の遺伝子転写を調節する.
- RsrRのDNA結合は,鉄と硫黄のクラスターによって調節され,+1と+2の酸化状態の間をサイクルします.
- 前回の研究では,トリプトファン9の回転を含むRsrRの重要な形状の変化が示されました.
研究 の 目的:
- RsrRリドックス状態,形状の変化,DNA結合の関係を解明する.
- RsrR機能におけるトリプトファン9の回転とヒスティジン33のプロトネーションの役割を調査する.
- 電子移転とタンパク質の構造動態を結びつけるメカニズムを理解する.
主な方法:
- トリプトファンの化学変化
- サイト・ダイレクト・ミュータジェネシス
- 結晶学と計算による化学研究
主要な成果:
- RsrRの露出状態 (Out) と埋められた状態 (In) は,それぞれ酸化状態と還元状態に対応する.
- ヒスティジン33は,クラスター還元によるpKaシフトにより,還元 (In) 状態で陽子化される.
- トリプトファン9の回転は,リドックスサイクル中の静電変化に対する二極モメントの反応によって引き起こされる.
結論:
- RsrRの酸化還元状態は,鉄と硫黄のクラスター変化を通じて,その形状とDNA結合能力を直接制御する.
- ヒスティジン33のプロトネーションは,クラスタの電子環境の影響を受け,減少状態の重要なイベントである.
- この研究は,タンパク質の機能を調節する電子移転の直接的な結果である新しいメカニズムを明らかにしています.
関連する概念動画
RNA Polymerase II Accessory Proteins
10.6K
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...
10.6K
RNA Polymerase II Accessory Proteins
3.7K
3.7K
Co-activators and Co-repressors
8.3K
Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into...
8.3K
Cooperative Binding of Transcription Regulators
7.1K
Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form...
7.1K
Cooperative Binding of Transcription Regulators
2.4K
2.4K
Transcriptional Regulation: Riboswitches
458
Riboswitches are RNA elements that regulate gene expression by altering their secondary structures in response to specific effector molecules. These elements, located in the leader regions of certain mRNAs, act as transcriptional regulators by toggling between alternative conformations to control downstream gene expression. Riboswitch-mediated regulation is a precise mechanism for modulating biosynthetic pathways, as exemplified by the riboflavin biosynthesis pathway in Bacillus...
458

