リボソームの出口トンネルは,差別ゲートとして機能します
Hitoshi Nakatogawa1, Koreaki Ito
1Institute for Virus Research and CREST, Japan Science and Technology Corporation, Kyoto University, Japan.
Cell
|March 15, 2002
まとめ
特定のリボソーム停止モチーフにより,SecMの翻訳が停止する. リボソームの成分におけるサプレッサー変異は,出口トンネルが新生タンパク質製品へのゲートとして機能することを示唆しています.
科学分野:
- 分子生物学は分子生物学である.
- タンパク質合成 タンパク質合成
- リボソームの機能
背景:
- SecMは,タンパク質の輸出機構によって変換が調節されるタンパク質です.
- リボソームから発生する新生タンパク質鎖は,リボソームの出口トンネルと相互作用することができます.
- 翻訳逮捕の正確なメカニズムとその規制は完全に理解されていません.
研究 の 目的:
- SecM翻訳のメカニズムを調査するために.
- SecM翻訳の調節に関与するリボソーム成分を特定する.
- 新生タンパク質製品差別におけるリボソーム出口トンネルの役割を明らかにする.
主な方法:
- サイト・ディレクテッド・ミュータジェネシスにより,SecMおよびリボソーム成分に突然変異を導入する.
- タンパク質合成と延長停止をモニターするためのインビトロトランスレーションアッセイ.
- 23SリボソームRNA (rRNA) とリボソームタンパク質L22における抑制器変異の分析.
主要な成果:
- SecMの特定の配列モチーフ (FXXXXWIXXXXGIRAGP) はプロリン残基を含み,リボソーム内の延長停止を誘導する.
- 23S rRNAとリボソームタンパク質L22の変異が特定され,この延長停止を抑制しました.
- これらの抑制器変異は,リボソームの出口トンネルの最も狭い部分を覆う残基にマッピングされます.
結論:
- 特定されたシーケンスのモチーフは,翻訳中に特定の停止点として機能します.
- リボソーム出口トンネルの狭い収縮は,新生ポリペプチド鎖を感知し,それに反応する上で重要な役割を果たします.
- リボソームのこの領域は,差別ゲートとして機能し,タンパク質の配列と構造に基づいてタンパク質の通過を制御します.
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