適合スイッチは,シェットナタンパク質II (FeSII) による酸素損傷からの窒素酵素保護を誘発する
Julia Schlesier1, Michael Rohde1, Stefan Gerhardt1
1Institute for Biochemistry, Albert-Ludwigs-Universität Freiburg , Albertstrasse 21, 79104 Freiburg, Germany.
Journal of the American Chemical Society
|December 15, 2015
まとめ
ダイアゾトロフにおける窒素酵素の保護は,シェットナタンパク質II (FeSII) の酸化還元依存型変化によって達成される. このメカニズムは,有酸素細菌の酸素損傷から窒素の固定を保護します.
科学分野:
- 生物化学
- 構造生物学
- 微生物学
背景:
- 窒素酵素はプロカリオットにおける必須の窒素固定を触媒するが,酸素に敏感である.
- ディアゾトロフは,有酸素環境で窒素酶を保護するために堅固なメカニズムを必要とします.
- シェットナタンパク質II (FeSII) は,窒素酵素成分と保護複合体を形成する.
研究 の 目的:
- Azotobacter vinelandii FeSIIの3次元構造を決定する
- 酸素依存の窒素酵素保護の分子基盤を解明する.
- ニトロゲンゼの形状的に保護された三重複合体をモデル化する.
主な方法:
- 2.1 Åの解像度でFeSII構造を決定するX線 difraktion.
- Azotobacter vinelandii FeSIIの生産と分離について
- FeSII結合と相互作用を調査するための保護測定法.
主要な成果:
- 二重のFeSIIタンパク質構造は2つの異なる形状を明らかにした.
- 鉄硫黄群の近くの拡張ループの酸化還元依存の再編成が確認された.
- FeSIIは活性化時に静電相互作用によって窒素酶複合体と結合する.
結論:
- FeSIIの確認された形状の変化は,酸素依存の窒素酶保護のための分子基盤を提供します.
- FeSIIは酸素の存在下で窒素酵素の機能を維持する上で重要な役割を果たします.
- FeSIIを含む窒素酸の保護された三元複合体のモデルが提案された.
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