リボソームのコトランスレーションタンパク質の折りたたみがリアルタイムで監視される

Wolf Holtkamp¹, Goran Kokic¹, Marcus Jäger¹

¹Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.

Science (New York, N.Y.)

|November 28, 2015

まとめ

新しく合成されたタンパク質はリボソームに折りたたまれますこの研究は,小さなタンパク質ドメインが翻訳中に急速に折り畳み,完成前にリボソーム内の構造を形成することを示しています.

科学分野:

分子生物学
バイオ物理学
タンパク質の折りたたみ

背景:

タンパク質ドメインは,リボソーム合成中に安定した三次構造を達成することができる.
コトランスレーションの折りたたみを理解することは,タンパク質の生化に不可欠です.

研究の目的:

翻訳中の小さなタンパク質ドメインのリアルタイム折り畳みを調査します.
コトランスレーションの折り畳みのメカニズムと運動を明らかにする.

主な方法:

高性能で復元された in vitro 変換システムを使用した.
合成中のタンパク質ドメインの折りたたみをリアルタイムで観察する.

主要な成果:

E. coli HemKのN端領域は,コトランスレーションによる折りたたみを受けます.
リボソームのペプチドトンネル内で折りたたみを開始し,コンパクトで非本来の状態を形成します.
ネイティブのような構造への再編成は,翻訳直後に発生し,折り畳み移行の速度は翻訳によって制限されます.

結論:

コトランスレーション式折り畳みは,小規模で本質的に高速に折り畳まれる領域の高速で自律的なプロセスです.
リボソームの閉じ込めは,早期の折りたたみ時の形状的な風景に影響します.
このメカニズムは,小さなタンパク質ドメインに共通している可能性があります.

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