翻訳80Sリボソームに関連したタンパク質伝導チャネルの構造
R Beckmann1, C M Spahn, N Eswar
1Laboratory of Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA. roland.beckmann@charite.de
Cell
|November 10, 2001
まとめ
研究者は,酵母リボソーム新生鎖複合体 (RNC) がSec61タンパク質伝導チャネル (PCC) と相互作用することを視覚化しました. この構造的洞察は,コトランスレーショントランスロケーションのバイナリモデルをサポートし,エンドプラズマ網膜へのタンパク質標的を簡素化します.
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
- 細胞生物学 細胞生物学
背景:
- Sec61複合体は,エンドプラズマ網膜のタンパク質伝導チャネル (PCC) を形成する.
- リボソーム新生連鎖複合体 (RNCs) は,ER膜のタンパク質転位を開始する.
- RNC-PCCの相互作用を理解することは,コトランスレーショントランスロケーションの解読に不可欠です.
研究 の 目的:
- 酵母RNCとSec61複合体の相互作用を構造的に特徴づけるために.
- ERをターゲットとするコトランスレーション性タンパク質の分子基礎を解明する.
- 転位時のリボソームチャネル複合体の機能モデルを提案する.
主な方法:
- 酵母RNCをシグナル配列で in vitro 組み立てました.
- RNC-Sec61複合体の免疫浄化について.
- 15.4 Åの解像度で構造再構築のための冷凍電子顕微鏡 (cryo-EM) です.
主要な成果:
- クリオ-EM構造は,RNCのP部位にSec61複合体と結合したtRNAを明らかにした.
- リボソーム成分とPCCの間には,狭いギャップを越えて4つの明確な関連が観察されました.
- Sec61複合体はコンパクトトリマーとして現れ,ダイナミックなrRNA要素 (拡張セグメント27) に影響を与えた.
結論:
- この研究は,RNC-Sec61複合体の高解像度構造のスナップショットを提供しています.
- この発見は,コトランスレーション性トランスロケーションの簡素化されたバイナリモデルを支持する.
- このモデルでは,リボソームチャネル複合体の2つの基本的な機能状態を翻訳します.
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