関連する実験動画
Updated: Jun 19, 2026
08:07
Single Molecule Fluorescence Energy Transfer Study of Ribosome Protein Synthesis
Published on: July 6, 2021
延長因子Gを持つリボソームの構造は,転位後の状態に閉じ込められている
Yong-Gui Gao1, Maria Selmer, Christine M Dunham
1MRC Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 0QH, UK.
Science (New York, N.Y.)
|October 17, 2009
まとめ
リボソームの結晶構造を,フッシド酸に閉じ込められた延長因子G (EF-G) で決定した. この構造は,EF-GがリボソームとtRNAとどのように相互作用して,翻訳を容易にするかを明らかにします.
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
- バイオケミストリー バイオケミストリー
背景:
- 延長因子G (EF-G) は,リボソーム媒介翻訳に不可欠なGTPaseである.
- EF-Gは,タンパク質合成中に転送RNA (tRNA) とメッセンジャーRNA (mRNA) の転位を促進する.
研究 の 目的:
- リボソーム転位中のEF-G機能の構造的メカニズムを解明する.
- EF-Gとリボソームとその関連分子との相互作用を視覚化するために.
主な方法:
- リボソーム-EF-G複合体の構造を決定するために,X線結晶学を用いた.
- 構造は3.6アングストームの解像度まで改良された.
- フジジ酸は,EF-Gを中間形状状態に捕まえるために使用されました.
主要な成果:
- 転位後の状態のEF-Gを持つリボソームの高解像度の結晶構造が得られました.
- EF-Gドメインとリボソーム成分 (L10-L12茎,L11領域) の間の相互作用が詳細に示されました.
- P部位におけるtRNAおよびmRNAとの相互作用におけるEF-GドメインIVの役割が明らかにされた.
- 移動性リボソーム茎の安定化は,より完全な構造的記述を提供した.
結論:
- 結晶構造は,EF-G媒介のリボソーム転移のメカニズムに関する原子レベルの洞察を提供します.
- 特定の相互作用は,リボソーム要素とEF-Gドメインが触媒と基板結合における役割を強調しています.
- この発見は,タンパク質合成の基本的プロセスについての理解を深めるものです.
関連する概念動画
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...
02:07Improving 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...
01:34Directing Proteins to the Rough Endoplasmic Reticulum
The organelle-specific signaling sequences direct proteins synthesized in the cytosol to their final destination like ER, mitochondria, peroxisomes, etc. Some of the proteins directed to ER are then trafficked via vesicles to other organelles within the cell or the extracellular environment through the Golgi complex. For example, the rough ER synthesizes soluble proteins for transportation to the lysosomes or secretion out of the cell. It can also synthesize transmembrane proteins that can...
01:27Post-translational Translocation of Proteins to the RER
A sizable fraction of proteins destined for ER are first synthesized in the cell cytosol and then transported across the ER membrane–a process called post-translational translocation. Similar to cotranslationally translocated proteins, these proteins also use the Sec translocon complex to enter the ER lumen.
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...
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,...
02:53Ribosomal 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,...