バクテリアの毒素RelEは,リボソームA部位におけるmRNAのコドン特異的な割れ目を示す
Kim Pedersen1, Andrey V Zavialov, Michael Yu Pavlov
1Department of Biochemistry and Molecular Biology, OU, University of Southern Denmark, Campusvej 55, DK-5230 Odense, Denmark.
Cell
|January 16, 2003
まとめ
Escherichia coli RelE毒素は,リボソーム内の特定のコドンにmRNAを分裂させ,タンパク質合成を阻害する. このプロセスはtmRNAによって逆転し,RelEを示唆する.
科学分野:
- バクテリア学 バクテリア学
- 分子生物学は分子生物学である.
- 遺伝学 遺伝学とは
背景:
- Escherichia coli relBEオペロンは,RelE-RelB.という毒素対抗毒素のペアをコードしています.
- RelBは,RelE媒介によるタンパク質合成の抑制をin vivoで逆転させることが知られている.
研究 の 目的:
- RelE媒介タンパク質合成阻害のメカニズムを調査する.
- RelE毒素の基板特異性と割れ部位を決定する.
- バクテリアの適応におけるRelEの役割を明らかにする.
主な方法:
- 精製されたRelE毒素を用いたインビトロ割れ分析.
- ジェルエレクトロフォレシスによるmRNA分裂産物の分析.
- 合成mRNA基板を使用してコドン特異性の決定.
主要な成果:
- RelEは,特にリボソームA部位内のmRNAを分割する.
- クリーバージは高いコドン特異性を持ち,優先的にストップコドン (UAG,UAA,UGA) と特定の感覚コドン (UCG,CAG) を標的にする.
- RelEは自由RNAを分解せず,リボソーム結合mRNAとの特定の相互作用を示しています.
結論:
- RelEはmRNAインターフェラーゼとして機能し,リボソームA部位内の特定のコドンを標的にします.
- RelEによるタンパク質合成の阻害は,tmRNAによって逆転する可能性が高い.
- RelEは,栄養素が少ない環境への細菌の適応を制御する役割を果たします.
関連する概念動画
01:23Types of RNA
61.3K
Overview
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
61.3K
01:44Termination of Translation
19.6K
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...
19.6K
02:28Leaky Scanning
4.5K
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R...
4.5K
01:29Coordination of Gene Expression Processes in Bacteria
1.1K
The DNA replication, transcription, and translation processes are intricately coupled in bacteria, allowing efficient gene expression and rapid protein synthesis. While this physical and functional coordination is advantageous, it introduces challenges that bacteria overcome through specific regulatory mechanisms.Coupling of Replication, Transcription, and TranslationThe coupling of replication, transcription, and translation is a hallmark of bacterial gene expression. As the replisome unwinds...
1.1K
01:29Translational Regulation
877
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,...
877
01:12Bacterial Toxins
148
Bacterial toxins are sophisticated virulence factors that enable pathogenic bacteria to interact with, invade, and damage host tissues. These toxins fall broadly into two types: protein exotoxins, which are secreted into the environment and target specific host receptors, and lipopolysaccharide endotoxins, which are structural components of the bacterial outer membrane released primarily during bacterial lysis or membrane shedding. Exotoxins generally act more selectively, binding to cell...
148