関連する実験動画
Updated: Nov 5, 2025

06:59
Nanomanipulation of Single RNA Molecules by Optical Tweezers
Published on: August 20, 2014
15.1K
preQ1リボスイッチのマイクロ秒折り,二次元光生命相関スペクトロスコーピーによって明らかになった生物学的重要性
Bidyut Sarkar1, Kunihiko Ishii1,2, Tahei Tahara1,2
1Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako 351-0198, Japan.
Journal of the American Chemical Society
|May 20, 2021
まとめ
この研究は,バチルス・サブティリスのpreQ1リボスイッチが遺伝子発現を制御するためにどのように形状を変えているかを明らかにしています. 折り畳みダイナミクスと,Mg2+とpreQ1のようなリガンドが結合し,遺伝子調節に影響を及ぼすことを詳細に説明しています.
科学分野:
- 分子生物学
- バイオ物理学
- 生物化学
背景:
- リボスイッチはバクテリアの遺伝子発現を制御する RNA 調節要素です
- トランスクリプションリボスイッチは,アプタマー領域の構成変化を利用して,遺伝子発現を運動的に調節する.
- これらのダイナミクスを理解することは 遺伝子の調節メカニズムを解読するのに不可欠です
研究 の 目的:
- Bacillus subtilis preQ1 リボスイッチアプタマー領域の構造動態を調査する.
- preQ1とMg2+の結合メカニズムを解明する.
- リボスイッチ機能におけるマイクロ秒の折り畳み/展開の役割を決定する.
主な方法:
- マイクロ秒の時間解像度を持つ二次元光寿命相関スペクトロスコーピー (2D FLCS).
- 折り畳み/展開のダイナミクスを特徴付けるための単分子データ分析.
- 過去の smFRET 研究と統合して,総合的な見方をする.
主要な成果:
- アプタマー領域は,ヘアピン (O),擬似結び目 (pF),およびH型擬似結び目 (fF) の3つの異なる構成状態を示している.
- Mg2+は,形状選択によってfF型に結合し,preQ1は,誘発的適合によってO → pF型に結合し,O → pFの折り畳みを加速する.
- PreQ1結合はfF形態を安定させ,10ミリ秒以上で有意な安定化が生じます.
結論:
- アプタマー領域の折りたたみ/展開のダイナミクスとエネルギー景観の詳細なイメージが得られました.
- マイクロ秒のダイナミクスはリボスイッチの生物学的機能にとって有意である.
- アプタマー領域構造ダイナミクスに基づく遺伝子発現制御のための分子機構が提案されている.
関連する概念動画
Transcriptional Regulation: Riboswitches
266
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...
266
Riboswitches
8.9K
Riboswitches are non-coding mRNA domains that regulate the transcription and translation of downstream genes without the help of proteins. Riboswitches bind directly to a metabolite and can form unique stem-loop or hairpin structures in response to the amount of the metabolite present. They have two distinct regions – a metabolite-binding aptamer and an expression platform.
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
8.9K
Ribosome Profiling
3.8K
Ribosome profiling or ribo-sequencing is a deep sequencing technique that produces a snapshot of active translation in a cell. It selectively sequences the mRNAs protected by ribosomes to get an insight into a cell’s translation landscape at any given point in time.
Applications of ribosome profiling
Ribosome profiling has many applications, including in vivo monitoring of translation inside a particular organ or tissue type and quantifying new protein synthesis levels.
The technique...
Applications of ribosome profiling
Ribosome profiling has many applications, including in vivo monitoring of translation inside a particular organ or tissue type and quantifying new protein synthesis levels.
The technique...
3.8K
Protein Dynamics in Living Cells
2.4K
Different fluorescence-based techniques are used to study the protein dynamics in living cells. These techniques include FRAP, FRET, and PET.
Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached...
Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached...
2.4K
Translational Regulation
301
Translational regulation in prokaryotes ensures efficient protein synthesis by controlling ribosome access to mRNA. This regulation is mediated by secondary RNA structures, including translational riboswitches, RNA thermometers, and small RNAs (sRNAs), which respond to intracellular and environmental signals to modulate gene expression.Translational RiboswitchesRiboswitches in the leader region of mRNAs can regulate translation by altering the accessibility of the Shine-Dalgarno (SD) sequence,...
301
Termination of Translation
26.4K
The large ribosomal subunit has several important structures essential to translation. These include the peptidyl transferase center (PTC) - which is the site where the peptide bond is formed - and a large, internal, water-filled tube through which the nascent polypeptide moves. This latter structure is called the Peptide Exit Tunnel, and it begins at the PTC and spans the body of the large ribosomal subunit. During translation, as the nascent polypeptide chain is synthesized, it passes through...
26.4K

