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内生菌MCE脂質トランスポーターの構造

  • 0Department of Cell Biology, New York University School of Medicine, New York, NY, USA.
Nature +

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2023年7月26日

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2023年7月26日

PubMedで要約を見る

まとめ

この要約は機械生成です。

ミコバクテリアの結核は 毒性を確保するために 栄養素を採取する必要があります 研究者らはMce1の脂質輸入機械の構造を明らかにし,その組立と菌糸体細胞膜の横断で脂質輸送のための新しい経路を明らかにした.

科学分野

  • 微生物学
  • 構造生物学
  • 生物化学

背景

  • Mycobacterium tuberculosisは,マクロファージ内の毒性と生存のために宿主栄養を収集します.
  • 哺乳類の細胞入り (MCE) タンパク質は,脂肪酸やコレステロールなどの脂質を菌糸体細胞膜に輸送する重要な毒性因子です.
  • 貨物輸送におけるMCEタンパク質複合体の組成と機能はほとんど不明である.

研究 の 目的

  • Mycobacterium smegmatisからのMce1脂質輸入装置の構造を決定する.
  • 脂質輸送におけるMCEタンパク質の組み立てメカニズムを解明する.
  • ミコバクテリアの細胞封筒にわたってMCE媒介による脂質輸入のモデルを提案する.

主な方法

  • Mce1複合体の構造を決定するための冷凍電子顕微鏡 (cryo-EM).
  • MCE複合子単位を特定するための AlphaFold2予測.
  • 脂質輸送メカニズムを理解するための生化学分析

主要な成果

  • Mce1複合体の冷凍-EM構造は,細胞封筒に広がる長方形のABCトランスポーターを示した.
  • 新しく曲げられた針状の領域が特定され,脂質輸送のための保護された水害性経路を形成した.
  • Mce1複合体内で新しいサブユニット LucB が特定されました.

結論

  • Mce1複合体は,ミコバクテリアの細胞封筒に及ぶ完全な脂質輸入装置を形成します.
  • 特定された構造は,MCE媒介による脂質輸送の仕組みについての洞察を提供します.
  • この研究は,M. tuberculosisの病原性にとって極めて重要な,菌糸体細胞封筒全体での脂質輸入の構造モデルを提供します.

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