亜基質のない外開き状態と,内開き状態のアポ状態の LeuT のX線構造
Harini Krishnamurthy1, Eric Gouaux
1Vollum Institute, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, USA.
Nature
|January 11, 2012
まとめ
神経伝達物質のナトリウムシンポーターに関する構造的な洞察は,基板結合がトランスポーターを閉じる方法を明らかにします. 新しい結晶構造は,外開いた状態と内開いた状態を明らかにし,イオンと基板の輸送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
- 神経科学は神経科学である.
背景:
- 神経伝達物質のナトリウムシンポーター (NSS) は,セロトニンやドーパミンなどの神経伝達物質をクリアし,シナプス伝達に不可欠です.
- 以前のNSSの同類であるLeuTの結晶構造は洞察を提供したが,鍵となるメカニズムに関する疑問は解明されなかった.
研究 の 目的:
- 外開いた状態と内開いた状態の LeuT の結晶構造を決定する.
- NSSにおける基板輸送とイオン転位の基礎となる構造変化を解明する.
主な方法:
- 形状特異の抗体断片で複合した LeuT ミュータントのX線結晶学.
- 超膜領域と細胞外ループにおける構造変化の分析.
主要な成果:
- 結晶構造は,外開きと内開きの形状で LeuT を明らかにします.
- サブストラット結合は,局所的な構造変化によって細胞外ゲートを閉じます.
- 内側に開いた状態は,大規模なドメインの方向転換,細胞外ベスティビルの閉塞,細胞内ベスティビルの開きを含みます.
結論:
- これらの構造は,NSSのメカニズムと薬による調節を理解するための枠組みを提供します.
- この発見は,イオンと基板が細胞質にどのように放出されるかを明らかにしています.
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