ニュクレオチドフリーでグルタチオンに結合したミトコンドリアのABCトランスポーターAtm1の結晶構造
Vasundara Srinivasan1, Antonio J Pierik, Roland Lill
1Institut für Zytobiologie, Philipps-Universität Marburg, Robert-Koch-Strasse 6, 35032 Marburg, Germany.
Science (New York, N.Y.)
|March 8, 2014
まとめ
酵母ミトコンドリアのABCトランスポーターAtm1は,鉄の調節に不可欠であり,構造的に分析されました. グルタチオンの結合形態は,鉄硫黄タンパク質の生体生成と関連する貧血に関する洞察を明らかにします.
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
- 細胞生物学 細胞生物学
背景:
- イーストのミトコンドリアのABCトランスポーターAtm1は,鉄硫黄タンパク質バイオゲネシスに必要な基質の輸出を容易にする.
- ATM1はグルタチオンとともに,細胞の鉄調節に重要な役割を果たしています.
- ヒトのオートログであるABCB7の欠陥は, sideroblastic anemia (XLSA/A) と関連しています.
研究 の 目的:
- Atm1関数の構造的基礎を解明する.
- Atm1とグルタチオンの相互作用を理解するために.
- XLSA/A.の基礎となる分子メカニズムについての洞察を提供するためです.
主な方法:
- 構造を特定するために,X線結晶学を用いた.
- 構造は,自由ATM1とグルタチオン結合ATM1に対して,それぞれ3.06アングストームと3.38アングストームで解明されました.
- 分析は,トランスポーターの内側に向き,オープンな形状に焦点を当てた.
主要な成果:
- 自由とグルタチオンに結合したAtm1の結晶構造は,内向きの開いた形状で得られた.
- グルタチオンの結合部位が特定され,XLSA/Aに変異した残留物を含み,内膜の近くにある.
- ヌクレオチドフリーATP結合ドメインは直接の相互作用を示さなかったが,二次体内のC末端ヘリックス相互作用によって安定化していた.
結論:
- 構造データは,Atm1-グルタチオンの相互作用のメカニズムと,鉄輸送におけるその役割を明らかにします.
- この発見は,ABCB7変異に関連した sideroblastic貧血の分子理解を提供します.
- C端末ヘリックス相互作用によるAtm1ダイマーの安定化は,ABC輸出者の間で保存された特徴である可能性があります.
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