鉄によるテンプレート指向型非酵素RNA複製の触媒化 (II)
Lin Jin1, Aaron E Engelhart2, Weicheng Zhang1
1Howard Hughes Medical Institute, Department of Molecular Biology, and Center for Computational and Integrative Biology , Massachusetts General Hospital , Boston , Massachusetts 02114 , United States.
Journal of the American Chemical Society
|October 19, 2018
まとめ
鉄 (II) イオン (Fe2+) は,前生物の地球上で早期のRNA複製を容易にしたのかもしれない. この研究は,Fe2+が非酵素RNA複製のマグネシウム (Mg2+) よりも優れた触媒であることを示し,生命の初期化学における重要な役割を示唆しています.
科学分野:
- 生命 研究 の 起源
- 前生物化学
- RNA世界仮説
背景:
- 非酵素型RNA複製は,プリバイオティックRNA複製を理解するために不可欠です.
- 以前のRNA複製モデルは,高濃度のマグネシウム (Mg2+) を要求していた.
- 初期の地球に豊富な鉄 (II) (Fe2+) は,RNAの折り畳みを促進するMg2+を模倣する.
研究 の 目的:
- プリバイオティックRNAの複製を触媒化するFe2+の可能性を調査する.
- 非酵素RNA複製におけるFe2+とMg2+の触媒効率を比較する.
主な方法:
- 2-メチリミダゾール活性化ヌクレオチドを用いた非酵素プライマー拡張および結合測定
- わずかに酸性から中性pHの条件下でFe2+とMg2+によって触媒化された反応速度の比較.
主要な成果:
- Fe2+はRNAプライマーの拡張と結合においてMg2+よりも優れた触媒活性を示した.
- 試験条件下ではFe2+でより速い反応率が観察されました.
- Fe2+はRNA複製を効果的に促進し,その前生物学的関連性を示唆しています.
結論:
- Fe2+はMg2+よりも重要なRNA複製段階においてより効果的な触媒である.
- 鉄 (II) はおそらく, RNA の複製と進化を促進する上で重要な役割を果たした.
- Fe2+は他の金属イオンと結合して 初期のRNAベースの生命を支えたのかもしれません
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