バクテリアの光調節型サイクリックヌクレオチド・フォスフォディエステラーゼの構造とメカニズム
Thomas R M Barends1, Elisabeth Hartmann, Julia J Griese
1Max Planck Institute for Medical Research, Department of Biomolecular Mechanisms, Jahnstrasse 29, 69120 Heidelberg, Germany.
Nature
|June 19, 2009
まとめ
研究者は,ブルーライトセンサー (BLUF) の光受容体であるBlrP1を特徴づけました. この研究は,光がどのようにフォスフォディエステラーゼドメインを活性化し,細菌の第2伝達体サイクル二次元GMP (c-di-GMP) を制御するかを明らかにしています.
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
- 微生物学 微生物学とは
背景:
- ブルーライトセンサー (BLUF) ドメインは,バクテリア,ユグレンゾア,菌類に見られるFAD染色体を使用した光受容体です.
- 機能的な出力ドメインを持つBLUFタンパク質の理解は限られており,それらの光活性化メカニズムに関する知識が妨げられています.
研究 の 目的:
- クレブシエラ肺炎菌の全長光受容体BlrP1を生化学的,構造的,および機械的に特徴づける.
- 出力ドメインを持つBLUFを含む光受容体の光活性化メカニズムを解明する.
主な方法:
- バイオケミカルアッセイ
- X線結晶グラフィーです.
- BlrP1の構造分析について
主要な成果:
- BlrP1はBLUFセンサと,サイクル二次元GMP (c-di-GMP) を水分解するEAL出力ドメインであるフォスフォディエステラーゼで構成されています.
- 結晶構造は,EALドメインのc-di-GMPフォスフォディエステラーゼのメカニズムを明らかにし,光の活性化経路を提案しました.
- BLUFドメインによるフォトンの吸収は,BlrP1ホモジマーの隣接するサブユニットのEALドメインをアロステリックに活性化します.
結論:
- BlrP1は,BLUF光受容体の新しいクラスであり,特徴的な光感知および信号伝達機構を有する.
- この研究は,バクテリアの第2伝達物質の調節に不可欠な,BLUFセンサーとEAL出力ドメインの間のアロステリック通信の洞察を提供します.
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