GTP アナログに結合した Ran を複合した Ran 結合ドメインの構造: 核輸送への影響
I R Vetter1, C Nowak, T Nishimoto
1Abteilung Strukturelle Biologie, Max-Planck-Institut für molekulare Physiologie, Dortmund, Germany.
Nature
|March 17, 1999
まとめ
ランタンパク質 (Ran protein) とは
科学分野:
- 分子生物学は分子生物学である.
- 細胞生物学 細胞生物学
- 構造生物学 構造生物学とは
背景:
- Ranタンパク質は,核輸送に不可欠な小さなGTP結合タンパク質です.
- RanはRan結合タンパク質とインポートリンベータのような分子と相互作用し,細胞プロセスを調節する.
- ラン結合ドメイン (RanBDs) は,これらの相互作用に関与する保存モチーフです.
研究 の 目的:
- 核毛孔複合体の重要な構成要素であるRanBP2とのRanの相互作用の構造的基礎を解明する.
- RanBDsがRanのGTPase活動と核輸送におけるその役割を調節するメカニズムを理解する.
主な方法:
- X線結晶学を用いて,GTPアナログ (Ran x GppNHp) に結合したRanの構造をヒトRanBP2.2の最初のRan結合ドメイン (RanBD1) と複合的に決定した.
主要な成果:
- RanBD1は,pleckstrin-homologyドメインの折りたたみを共有しています.
- Ran x GppNHpのスイッチ-I領域は,構造的にはカノニカルRas GppNHpに似ている.
- ランのカーボキシ端末はRanBD1の周りを包み,端末を隔離し,輸送因子からランの解離を促進する"抱擁"を形成します.
結論:
- この相互作用は,Rasに関連するタンパク質のための新しいスイッチメカニズムを表しています.
- Ran-RanBP2の相互作用は,ranGAPによるGTPの水解を促進し,核輸送を調節する.
- この発見は,細胞輸送におけるタンパク質-タンパク質相互作用の調節に関する新しい洞察を提供します.
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