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Updated: May 9, 2026
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Xenopus laevis as a Model to Identify Translation Impairment
Published on: September 27, 2015
翻訳強化剤は,リボソームが翻訳開始から解放されるのを改善します
Shuntaro Takahashi1, Hiroyuki Furusawa, Takuya Ueda
1Department of Biomolecular Engineering, Tokyo Institute of Technology, B-53, 4259 Nagatsuda, Midori-ku, Yokohama 226-8501, Japan.
Journal of the American Chemical Society
|August 10, 2013
まとめ
翻訳強化剤とシャイン・ダルガーノ配列は,リボソームの動きを調節することにより,タンパク質合成を促進します. これらの要素を最適化すると,アデニンの繰り返しと同様に,翻訳効率が大幅に向上します.
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:
- 細菌の翻訳開始は,リボソーム-mRNA相互作用のためのシャイン-ダルガーノ (SD) 配列に依存しています.
- 初期部位からのリボソーム解離は,下流翻訳に不可欠です.
- リボソームタンパク質S1と相互作用するトランスレーションエンハンサーは,タンパク質の生合成を増やすことが知られているが,そのメカニズムは不明である.
研究 の 目的:
- SD配列とトランスレーションエンハンスターの30Sリボソームサブユニット結合キネティクスに対するSD配列とトランスレーションエンハンスターの影響を調査する.
- これらのシーケンスが翻訳効率にどのように影響するかを判断する.
主な方法:
- 30S リボソームサブユニットとmRNA変異体間の結合運動の分析.
- 異なったシーケンス条件下での翻訳効率の測定.
- 解離速度の役割を理解するための運動モデリング.
主要な成果:
- SDとエンハンサーの両方の配列を持つmRNAはタンパク質合成を増加させましたが,解離率 (koff) を増加させることで30Sサブユニット-mRNAの相互作用を不安定化しました.
- SDとエンハンサーの配列間のアデニン配列 (A20) のタンデムリピートにより,翻訳効率が16倍に増加しました.
- トランスレーションエンハンサーとSD配列は,リボソームの初期部位からの放出を共同で調節する.
結論:
- SD配列とトランスレーションエンハンサーの相互作用は,初期部位でのリボソーム動態を調節する.
- これらの規制要素は,下流のコーディング地域における翻訳効率の重要な決定要因である.
- A20リピートなどの要素を組み込んだ戦略的配列設計は,タンパク質の生物合成を大幅に改善することができます.
関連する概念動画
02:07Improving Translational Accuracy
Base complementarity between the three base pairs of mRNA codon and the tRNA anticodon is not a failsafe mechanism. Inaccuracies can range from a single mismatch to no correct base pairing at all. The free energy difference between the correct and nearly correct base pairs can be as small as 3 kcal/ mol. With complementarity being the only proofreading step, the estimated error frequency would be one wrong amino acid in every 100 amino acids incorporated. However, error frequencies observed in...
02:07Improving Translational Accuracy
Base complementarity between the three base pairs of mRNA codon and the tRNA anticodon is not a failsafe mechanism. Inaccuracies can range from a single mismatch to no correct base pairing at all. The free energy difference between the correct and nearly correct base pairs can be as small as 3 kcal/ mol. With complementarity being the only proofreading step, the estimated error frequency would be one wrong amino acid in every 100 amino acids incorporated. However, error frequencies observed in...
01:44Termination of Translation
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...
02:33Initiation of Translation
Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
02:33Initiation of Translation
Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
01:31Translation
Lesson: Translation
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life