菌類と植物のアセトヒドロキシ酸合成物の構造
Thierry Lonhienne1, Yu Shang Low2, Mario D Garcia2
1School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia. t.lonhienne@uq.edu.au.
Nature
|July 9, 2020
まとめ
アセトヒドロキシ酸合成酵素 (AHAS) の構造は,保存されたマルタのクロス構造を示している. この発見は,枝分かれ鎖アミノ酸の生物合成がどのように調節され,ハービシドがAHASをどのように標的としているかを明らかにする.
科学分野:
- 生物化学
- 酵素学
- 構造生物学
背景:
- アセトヒドロキシ酸合成酵素 (AHAS) またはアセトラクタ酸合成酵素は,分岐鎖アミノ酸の生物合成に不可欠です.
- AHASは50以上の商用除草剤の有効な標的である.
- 酵素は,最適の機能のために,触媒と調節の両方のサブユニットを必要とします.
研究 の 目的:
- AHAS複合体の構造的組織を解明する.
- 触媒と調節サブユニットのコミュニケーションを理解する.
- 異なる王国のAHAS建築の保存を調査する.
主な方法:
- X線結晶学を用いて,Saccharomyces cerevisiaeとArabidopsis thalianaのAHAS複合体の構造を決定した.
- Mycobacterium tuberculosis AHAS複合体の比較構造分析が行われました.
主要な成果:
- 制御サブユニットはコアを形成し,触媒サブユニットダイマーが付属し,マルタの十字架を形成します.
- 構造的な洞察は,ブランチチェーンアミノ酸による酵素活性化とフィードバック阻害の経路を明らかにします.
- Mycobacterium tuberculosisのAHAS複合体は,進化的保存を示唆する類似した構造を持っています.
結論:
- AHASの保存されたマルタのクロスアーキテクチャは,分岐鎖アミノ酸のバイオシンセシスの機能に不可欠です.
- この構造を理解することで,除草剤の設計と耐性管理の基礎となる.
- 構造的な保存は,この酵素複合体の進化的重要性を強調しています.
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