Enterococcus hirae V1-ATPaseの回転機構は,非対称な結晶構造に基づいている
Satoshi Arai1, Shinya Saijo, Kano Suzuki
1Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan.
Nature
|January 22, 2013
まとめ
空腔ATPases (V-ATPases) は,がんや骨粗鬆症の治療において重要な陽子ポンプであり,薬物標的である. この研究は,V(1)-ATPaseの高解像度の非対称構造を明らかにし,その回転モーター機構を明らかにします.
科学分野:
- バイオケミストリー バイオケミストリー
- 構造生物学 構造生物学とは
- 分子生物物理学 分子生物物理学
背景:
- 真空アタパース (V-ATPases) は,細胞膜に不可欠な陽子ポンプであり,骨再吸収と癌転移に関与しています.
- V(1) 部分は回転モーターとして機能するが,その正確な分子機構は,限られた高解像度構造データのために不明である.
- 以前の研究では,Enterococcus hirae V(1) -ATPaseのインビトロ発現,浄化,再構成が確立されました.
研究 の 目的:
- ヌクレオチドフリーおよびヌクレオチド結合のV(1) -ATPASE A(3) B(3) コンプレックス.の高解像度非対称構造を決定する.
- V(1) -ATPASE回転モーターの分子メカニズムを解明するために.
- V-ATPasesにおけるヌクレオチド結合とATP水解に関する洞察を提供するため.
主な方法:
- X線結晶学 (2.8 Å と 3.4 Å の解像度) を用いて,ヌクレオチドフリーとヌクレオチドに結合したV(1) -ATPase A(3) B(3) コンプレクスの非対称構造の決定.
- ヌクレオチドフリーとヌクレオチド結合のV(1)-ATPase (2.2 Åと2.7 Åの解像度) の結晶構造の決定.
主要な成果:
- ヌクレオチドフリー (2.8 Å) とヌクレオチド結合 (3.4 Å) V(1) -ATPASE A(3) B(3) 複合体の非対称な構造が報告されています.
- ヌクレオチド結合によって誘発される形状の変化を観察し,協力的で右向きの回転結合順序を示唆した.
- ヌクレオチドフリー (2.2 Å) とヌクレオチド結合 (2.7 Å) の結晶構造を決定したV(1)-ATPase.
- DF複合体の結合時により密集した核酸結合部位を特定した.
- ATPの水解は,保存されたアルギニン残基の接近によって刺激されると示されています.
結論:
- この研究は,V(1) -ATPaseの回転メカニズムを初めて高解像度で撮影したものです.
- この発見は,V-ATPaseの機能に不可欠な形状の変化と協力的な核酸結合を明らかにしています.
- これらの構造は,V-ATPaseの活性を理解し,標的治療を開発するための分子基盤を提供します.
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