ウラシルトランスポーターURAAの構造とメカニズム
Feiran Lu1, Shuo Li, Yang Jiang
1State Key Laboratory of Bio-membrane and Membrane Biotechnology, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
Nature
|March 23, 2011
まとめ
研究者は,Escherichia coli uracil/H(+) シンポーター UraA の結晶構造を決定し,その新しい折り畳みと核塩基輸送のメカニズムを明らかにしました. これは,核塩基/アスコルベートトランスポーター (NAT) タンパク質の機能に関する重要な洞察を提供します.
科学分野:
- 構造生物学 構造生物学とは
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
背景:
- ヌクレオベース/アスコルバートトランスポーター (NAT) タンパク質は,ヌクレオベース/カチオンシンポーター2 (NCS2) タンパク質とも呼ばれ,すべての生命界でヌクレオベース吸収を促進し,哺乳類ではビタミンCの輸送を促進します.
- 機能的研究にもかかわらず,NATファミリーメンバーの詳細な構造情報は不足しています.
研究 の 目的:
- 代表的なNATタンパク質の結晶構造を決定することによって,核塩基輸送の構造的基礎を解明する.
主な方法:
- X線結晶学を用いて,Escherichia coli uracil/H(+) シンポーター (UraA) と uracil.complex の構造を決定した.
- 構造は2.8 Åの解像度で解像しました.
主要な成果:
- UraAの結晶構造は,反転した2つの繰り返しに編成された14のトランスメブランセグメントを含む新しい折り畳みを明らかにしました.
- 超膜セグメント3と10の間にある独特の対反パラレルβ鎖のペアは,構造的組織と基板結合において決定的な役割を果たします.
- UraAの構造は,コアとゲートドメインに分かれ,そのインターフェイスに uracil が配置され,主にコアドメインの残留物によって調整されます.
結論:
- 決定された構造は,NATタンパク質の最初の原子レベルの見方を提供します.
- 構造分析は,ゲート領域の構成変化によって媒介される交替的なアクセスメカニズムを示唆しています.
- この研究は,核塩基および関連する分子の輸送機構を理解するための基礎を築いています.
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