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Tボックスリボスイッチ幹Iドメインの共同結晶構造は,その同類のtRNAと複合しています
Jinwei Zhang1, Adrian R Ferré-D'Amaré
1National Heart, Lung and Blood Institute, 50 South Drive, MSC 8012, Bethesda, Maryland 20892-8012, USA.
Nature
|July 30, 2013
まとめ
Tボックスリボスイッチは,コンパクトな幹Iドメインを使用して転送RNA (tRNA) を結合し,細菌における遺伝子調節のための新しいメカニズムを明らかにします. この相互作用は,栄養の変化に適応するために不可欠であり,アンチコドンを超えたtRNAアーキテクチャの特定の認識が含まれています.
科学分野:
- 分子生物学は分子生物学である.
- 構造生物学 構造生物学とは
- 遺伝学 遺伝学とは
背景:
- Tボックスリボスイッチは,グラム陽性細菌の重要な遺伝要素であり,細胞のニーズに対応して遺伝子発現を制御します.
- アミノアシル-tRNA合成酵素や他のタンパク質を調節する tRNA アミノアシレーションレベルを感知することで,タンパク質合成に不可欠です.
- TボックスリボスイッチによるtRNA認識の正確な構造的メカニズム,特にその保存された幹Iドメインは,まだ完全に理解されていません.
研究 の 目的:
- Tボックスリボスイッチ幹Iドメインによる特異的および高親和性移転RNA (tRNA) 結合の構造的基礎を解明する.
- オセアノバチルス・イヘイエンシス (Oceanobacillus iheyensis glyQ stem I) とその同類のtRNAとの相互作用を原子解像度で特徴づけること.
- この相互作用がバクテリアのtRNA依存の転写調節にどのように寄与するかを理解する.
主な方法:
- tRNA結合と親和性 (Kd ~150 nM) に対してT-box幹Iの必要性と十分性を決定する生化学的分析.
- 高解像度 (3.2 Å) の冷凍電子顕微鏡で,Tボックス幹I-tRNA複合体の構造を決定する.
- 構造分析は,主要な分子間接触と構造変化を特定するために行われます.
主要な成果:
- T-box幹Iドメインだけでは,特定の,高親和性tRNA結合に十分である.
- 構造は,L型tRNAを揺さぶるC型幹Iを明らかにし,広範囲なインターフェース (1,604 Å2) を形成します.
- 認識には,アンチコドン-スペシファーのペアリングと,tRNAの肘とのTループの相互作用の両方が含まれており,他のRNA-タンパク質複合体を模倣します.
結論:
- Tボックスリボスイッチは,コンパクトなmRNAドメインに対して前例のない戦略を採用し,アンチコドンだけでなく,全体的なtRNAアーキテクチャを認識します.
- 柔軟なtRNAと幹Iの間の相互誘発的フィット,保存された修正を使用し,特定の結合のための高形状の互補性を駆動します.
- この詳細な構造的な理解は,tRNA認識メカニズムとTボックス媒介遺伝子調節の収束進化の洞察を提供します.
関連する概念動画
RNA Structure
The basic structure of RNA consists of a string of ribonucleotides attached by phosphodiester bonds. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation.
Different Types of RNA Have the Same Basic Structure
There are three main types of ribonucleic acid (RNA) involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three...
Different Types of RNA Have the Same Basic Structure
There are three main types of ribonucleic acid (RNA) involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three...
RNA Structure
Overview
The basic structure of RNA consists of a five-carbon sugar and one of four nitrogenous bases. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation.
Different Types of RNA Have the Same Basic Structure
There are three main types of ribonucleic acid (RNA): messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three RNA types consist of a...
The basic structure of RNA consists of a five-carbon sugar and one of four nitrogenous bases. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation.
Different Types of RNA Have the Same Basic Structure
There are three main types of ribonucleic acid (RNA): messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three RNA types consist of a...
RNA Structure
Overview
The basic structure of RNA consists of a five-carbon sugar and one of four nitrogenous bases. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation.
Different Types of RNA Have the Same Basic Structure
There are three main types of ribonucleic acid (RNA): messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three RNA types consist of a...
The basic structure of RNA consists of a five-carbon sugar and one of four nitrogenous bases. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation.
Different Types of RNA Have the Same Basic Structure
There are three main types of ribonucleic acid (RNA): messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three RNA types consist of a...
Riboswitches
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...
Transcriptional Regulation: Riboswitches
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...
Nucleic Acid Structure
The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′ to 3′ phosphodiester linkage.
DNA Structure
DNA has a double-helix structure. The...
DNA Structure
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