リボソーム内の転送RNAの移動における中間状態
1Thimann Laboratory, University of California, Santa Cruz 95064.
Nature
|November 9, 1989
まとめ
転移RNA (tRNA) のリボソームへの転位は,2つの段階で行われます. 最初のステップは,tRNA受容体末端の自発的な動きを伴うが,第2ステップでは,アンチコドンの末端の動きのために延長因子EF-Gが必要である.
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
- 構造生物学 構造生物学とは
背景:
- リボソームの機能は,タンパク質合成の中心にある.
- 転送RNA (tRNA) 分子は,アミノ酸をリボソームに運ぶ.
- トランスレーション中のtRNAの動きを理解することは,タンパク質合成機構の解読に不可欠です.
研究 の 目的:
- タンパク質合成中のtRNA転位の段階的なメカニズムを解明する.
- tRNAの移動における異なるリボソームサブユニットと延長因子の役割を調査する.
主な方法:
- tRNAの位置を監視するために,直接の化学的足跡が使用されました.
- 分析は,転位の自発的および因子促進のステップに焦点を当てました.
主要な成果:
- tRNAのトランスロケーションは,2つの段階で行われます.
- 最初のステップは,ペプチド結合形成後の発生であり,tRNA受容体末端の自発的な動きを含み,ハイブリッドリボソーム結合状態につながる.
- 第2段階は,延長因子EF-Gによって促進され,tRNA抗コドンの末端とmRNAが小さなリボソームサブユニットに相対的に移動することを含む.
結論:
- リボソーム媒介のtRNAトランスロケーションは,多段階のプロセスです.
- tRNA受容体とアンチコドン末端の異なる動きは,異なるメカニズムによって調節されます.
- 延長因子EF-Gは,tRNA転位の第2段階において重要な役割を果たします.
関連する概念動画
02:53Ribosomal RNA Synthesis
Ribosome synthesis is a highly complex and coordinated process involving more than 200 assembly factors. The synthesis and processing of ribosomal components occurs not only in the nucleolus but also in the nucleoplasm and the cytoplasm of eukaryotic cells.
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
02:36Transfer RNA Synthesis
One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases.
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
02:22Regulated mRNA Transport
In eukaryotes, transcription and translation are compartmentalized; an mRNA is first synthesized in the nucleus and then selectively transported to the cytoplasm for protein synthesis. Before transport, a pre-mRNA undergoes several steps of post-transcriptional modifications including splicing, 5' capping, and the addition of a poly-adenine tail. Various proteins bind to the pre-mRNA during these modifications. The mRNA transport takes place with the help of multiple proteins playing specific...
02:36Transfer RNA Synthesis
One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases.
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
02:53Ribosomal RNA Synthesis
Ribosome synthesis is a highly complex and coordinated process involving more than 200 assembly factors. The synthesis and processing of ribosomal components occurs not only in the nucleolus but also in the nucleoplasm and the cytoplasm of eukaryotic cells.
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
02:22Regulated mRNA Transport
In eukaryotes, transcription and translation are compartmentalized; an mRNA is first synthesized in the nucleus and then selectively transported to the cytoplasm for protein synthesis. Before transport, a pre-mRNA undergoes several steps of post-transcriptional modifications including splicing, 5' capping, and the addition of a poly-adenine tail. Various proteins bind to the pre-mRNA during these modifications. The mRNA transport takes place with the help of multiple proteins playing specific...