アーティオダクティルリボヌクレアーススーパーファミリーの進化史を再構築
T M Jermann1, J G Opitz, J Stackhouse
1Department of Chemistry, ETH Zürich, Switzerland.
Nature
|March 2, 1995
まとめ
研究者らは,古代のタンパク質配列をパルシモニーを使って再構築した. 古代のリボヌクレアゼ (RNase) の活性が増加し,消化性RNaseが,アーティオダクティルの非消化性祖先から進化したことを示唆しました.
科学分野:
- 進化生物学の進化生物学について
- 分子進化は分子進化である.
- バイオケミストリー バイオケミストリー
背景:
- タンパク質の進化は,既存の親戚から祖先の配列を再構築することによって研究することができます.
- パルシモニーとは,進化的変化を最小限に抑え,祖先の配列を推論する方法です.
- リボヌクレアゼ (RNases) は,RNA代謝に関与する酵素で,さまざまな機能を持っています.
研究 の 目的:
- アーティオダクティルの系統内の古代のRNaseタンパク質配列を再構築し,特徴づけること.
- RNase機能の進化的変化と,生理学的適応との相関を調査する.
- 合理的な古代のタンパク質配列を再構築する際のパルシモニーの有効性を評価する.
主な方法:
- 控えめなアプローチを用いた13の古代RNase配列の再構築.
- 復元された古代RNaseタンパク質の実験室での合成と生化学的特徴付け.
- 二重鎖RNAに対する触媒活性の比較分析.
主要な成果:
- 復元された古代RNase配列は,その性質に基づいて妥当であることが判明しました.
- 祖先のアルティオダクティルRNase.で,二重鎖RNAに対する触媒活性が5倍に増加することが観察されました.
- この機能的シフトは,歯類における歯類の消化の出現と相関しています.
結論:
- パルシモニアは,機能的な古代タンパク質を再構築するための有効な方法です.
- アーティオダクティルの消化性RNaseの進化は,消化性でない祖先形態からの移行を伴う可能性が高い.
- 進化的タンパク質再構築は,生理学的機能の適応についての洞察を提供します.
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