ディフタミド生物合成には,鉄硫黄酵素によって生成された有機根子が必要である
Yang Zhang1, Xuling Zhu, Andrew T Torelli
1Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA.
Nature
|June 19, 2010
まとめ
翻訳延長因子2に不可欠なディフタミド生物合成は,新しい鉄硫黄酵素Dph2.2を特定することによって解明されます. この酵素は,S-アデノシル-l-メチオニンを特異的に利用して,ラジカルを生成し,この重要な改変に関する理解を深める.
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- 酵素学 酵素学とは
背景:
- ディフタミドは,古生物と真核生物のトランスレーション延長因子2に特異な翻訳後の改変である.
- この変異はディフテリア毒素の標的である.
- S-アデノシル-l-メチオニン (SAM) を含むディフタミド生物合成の初期段階は,以前は十分に理解されていませんでした.
研究 の 目的:
- ディフタミド生物合成の最初のステップのメカニズムを解明する.
- アーケオンPyrococcus horikoshii.のこの初期段階に起因する酵素を特定し,特徴づけること.
主な方法:
- Dph2酵素の構造分析.
- 酵素の活性とメカニズムを研究するための生化学的分析.
- 鉄硫黄のクラスターが触媒で果たす役割に関する調査.
主要な成果:
- 新しい鉄硫黄クラスター酵素Dph2は,ディフタミド生物合成の最初のステップに不可欠であると特定されました.
- Dph2はホモジマーであり,各モノメアは [4Fe-4S] クラスタを結合する.
- Dph2は,SAMから,3-アミノ-3-カルボキシプロピルラジカルを生成することで,C-C結合形成を触媒化し,SAMのラジカル酵素とは異なり,SAMから3アミノ-3-カルボキシプロピルラジカルを生成します.
結論:
- Pyrococcus horikoshii Dph2は,SAMに依存する, [4Fe-4S]を含む酵素の新しいクラスを表しています.
- 酵素は,ディフタミド生物合成における前例のない化学反応を触媒化する.
- この発見は,翻訳後の改変の基本的メカニズムについての重要な洞察を提供します.
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