MarK,多重芳香単体分解に必要なノボスフィンゴビウムアロマティシボランスキナーゼ
Benjamin W Hall1, Jeanette C Neri1, Craig A Bingman2
1Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, University of Wisconsin-Madison, Wisconsin, USA.
The Journal of biological chemistry
|August 21, 2025
まとめ
研究者はノボスフィンゴビウム・アロマティシボランスを,リグニン由来の芳香化合物であるアセトバニロンを代謝するように設計した. Saro_ 1862 (MarK) の単一のアミノ酸変異は,アセトバニロンのリン酸化率を増加させ,アセトバニロンの成長を可能にしました.
科学分野:
- 微生物の代謝と酵素工学
- バイオテクノロジーと再生可能資源
背景:
- アロマティック化合物は産業に不可欠ですが,主に石油から採取されます.
- リグニンは再生可能な植物ポリマーで 芳香化合物の豊富な源です
- Novosphingobium aromaticivoransは,いくつかのリンニン誘導体を代謝することができるが,アセトバニロンは代謝できない.
研究 の 目的:
- Novosphingobium aromaticivoransがアセトバニロンを唯一の炭素源として利用できるようにする.
- アセトバニロン代謝の遺伝的基礎を N. アロマチビランスで特定する.
- アセトバニロンのリン酸化を司る酵素を特徴づける.
主な方法:
- N.aromaticivoransの適応的な実験室での進化
- アセトバニロンの利用を可能にする変異を特定するための遺伝分析
- 酵素の活性と構造を特徴付けるための生化学的測定とタンパク質結晶学.
主要な成果:
- アセトバニロンによる成長に不可欠であるとして,Saro_ 1862における単一のアミノ酸置換 (E16K) が特定された.
- MarK E16Kの変種は,ATP依存のアセトバニロンリン酸化率が約1600倍増加している.
- リコンビナントMarK E16Kは複数の芳香化合物をリン酸化し,UPF0261ドメインの触媒活性を定義する.
結論:
- MarK酵素 (Saro_1862) は新しい多重芳香キナーゼである.
- E16Kの置換は,そのATP結合部位を変更することによって,MarKの活性を増強する.
- 芳香代謝の特定された経路は,細菌の系統系全体にわたって保存されている可能性が高い.
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