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プロカリオットのフラゲルフィラメントの超回転における収束進化
Mark A B Kreutzberger1, Ravi R Sonani1, Junfeng Liu2
1Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22903, USA.
Cell
|September 3, 2022
まとめ
バクテリアとアーカイアの鞭状繊維は 運動性を超えたコイルです 原子構造は,これらの異なった繊維が安定した超回転をどのように達成するかを明らかにし,微生物の移動のための収束進化を示唆しています.
科学分野:
- 微生物学
- 構造生物学
- バイオ物理学
背景:
- バクテリアと古生物のフラゲルフィラメントは運動に不可欠である.
- 古代のフラゲルフィラメントは構造的に細菌のフィラメントとは異なり,細菌型IVピリに似ています.
- これらのフィラメントがトルション・ストレスの下で安定したスーパーコイルを形成するメカニズムは,構造データがないため不明のままである.
研究 の 目的:
- 超巻きの細菌と古代生物の鞭状繊維の原子構造を解明する.
- プロカリオットの運動性構造におけるスーパーコイリングの構造的基礎を理解する.
- 安定した超螺旋形状の形成における潜在的収束進化を調査する.
主な方法:
- 高解像度構造を得るために,冷凍電子顕微鏡 (cryo-EM) が利用されました.
- 細菌と考古学的鞭状フィラメントの両方のために原子模型が構築され,精製されました.
- プロトフィラメントの形状とプロトマー間のインターフェースの分析が行われました.
主要な成果:
- 超コイルされた細菌のフラジェラフィラメントの原子構造は11の異なるプロトフィラメント構造と3つのクラス間のプロトメアインターフェイスを明らかにした.
- 超回転したアーカイアルフラゲラーフィラメントの原子構造は,10つの異なる形状を持つ10の原形フィラメントによって形成された超回転の幾何学を示した.
- 独特のプロトメア間の断絶が,アーカイアルフラゲラーフィラメントのスーパーコイル構造内でシームを形成していることが確認された.
結論:
- Cryo-EMは,鞭状フィラメントの超回転の構造的基礎について,原子レベルで洞察を提供します.
- バクテリアと古代生物の鞭状フィラメントには 機能的な類似性にもかかわらず 異なる構造的メカニズムが 基礎となっている.
- 収束進化は,生命の両方の領域で微生物の移動を可能にする,安定した超螺旋形状の幾何学の発展を説明する可能性がある.
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