B12-ラジカルSAM酵素PoyCは,ポリテオナミド生物合成中にバリンCβ-メチル化を触媒する
Aubérie Parent1, Alain Guillot1, Alhosna Benjdia1
1Micalis Institute, ChemSyBio, INRA, AgroParisTech, Université Paris-Saclay , F-78350 Jouy-en-Josas, France.
Journal of the American Chemical Society
|December 10, 2016
まとめ
研究者らは,PoyCをペプチドCβメチル化を行う最初のB12依存性S-アデノシルメチオニン酵素と特定した. この発見は,ポリテオナミド生物合成とB12根 S-アデノシルメチオニン酵素の理解を進めている.
科学分野:
- 生物化学
- 分子生物学
- 自然製品合成
背景:
- リボソームで合成されたペプチドと翻訳後のペプチド (RiPP) は,薬学的な用途を持つ多様な自然製品のクラスです.
- ポリテオナミドAは,C-メチル化を含む独特の翻訳後の改変を特徴とするRiPPである.
- これらのCメチレーションを触媒化するために,2つの過激なS-アデノシルメチオニン (rSAM) 酵素,PoyBとPoyCが提案された.
研究 の 目的:
- 推定 rSAM 酵素 PoyC の in vitro 活動を調査する.
- PoyCがペプチドCβメチル化を触媒するかどうかを判断する.
- RiPP生物合成におけるB12依存型rSAM酵素のメカニズムを解明する.
主な方法:
- PoyCを用いたインビトロ酵素測定
- S-アデノシルホモシステインと5'-デオキシアデノシンを含む反応産物の分析
- 酵素内のB12共因子 (MeCbl) の特徴化
主要な成果:
- PoyCは,最初のB12依存型rSAM酵素として,ペプチドCβメチル化を触媒として確認された.
- 酵素はメチル基をS-アデノシルメチオニンからl-バリン残基に転送する.
- 凝固結合メチルコバラミン (MeCbl) コファクターが特定され,メチル群を触媒作用で移す.
結論:
- PoyCの活動は,ポリテオナミドの生物合成に関する新しい洞察を提供します.
- この研究は,リボソームペプチドの改変におけるB12-rSAM酵素の重要な役割を明らかにしています.
- この発見は,B12依存酵素とその触媒機構の既知のレパートリーを拡張します.
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