細菌間NAD ((P) ((+)) 毒素は,標的細胞に届くために延長因子Tuを必要とします
John C Whitney1, Dennis Quentin2, Shin Sawai1
1Department of Microbiology, University of Washington, Seattle, WA 98195, USA.
Cell
|October 13, 2015
まとめ
プセドモナス・エアルギノサ
科学分野:
- 微生物学
- バクテリア病原性
- 分子生物学
背景:
- タイプVI分泌システム (T6S) は,細菌間毒素の放出を媒介し,微生物群を形成する.
- Pseudomonas aeruginosaはT6Sを利用して,効果タンパク質を競合する細菌に注入する.
研究 の 目的:
- Pseudomonas aeruginosaのT6S毒素 Tse6の作用機構と細胞への侵入を解明する.
- Tse6の構造的特徴と宿主因子との相互作用を特徴づける.
主な方法:
- X線結晶学を用いたTse6の構造分析
- Tse6の酵素活性を決定する生化学的測定法
- 電子顕微鏡でT6S装置と毒素複合体を可視化する
- 細菌の遺伝学で 相互作用相手を特定する
主要な成果:
- Tse6は,標的細胞における必須の二核酸NADとNADPを分解する.
- Tse6はモノADPリボシルトランスフェラーゼと構造的に類似しているが,ユニークなループを持っている.
- Tse6の標的細胞への侵入には,翻訳延長因子Tu (EF-Tu) との結合が必要である.
- Tse6,EF-Tu,および他のタンパク質は,毒素の輸出とチャペロン活動のためのより大きなアセンブリを形成します.
結論:
- Tse6は重要な細胞代謝物質を枯渇させ,強力な毒素として機能する.
- EF-TuはTse6の配達に重要な受容体として作用します.
- この研究は,細菌におけるT6S経由の細胞間毒素伝達に関する詳細なメカニズムを明らかにした.
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