歴史的な偶然性と,グルココルチコイド受容体の進化におけるその生体物理的根拠
Michael J Harms1, Joseph W Thornton2
11] Institute of Molecular Biology and Department of Chemistry &Biochemistry, University of Oregon, Eugene, Oregon 97403, USA [2] Departments of Human Genetics and Ecology &Evolution, University of Chicago, Chicago, Illinois 60637, USA.
Nature
|June 17, 2014
まとめ
進化の歴史は,珍しい偶然の出来事によって形作られました. 祖先のグルココルチコイド受容体 (GR) の機能変化に必要な特定のタンパク質変異は,生理学的制約のために例外的にまれでした.
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.
- バイオフィジックス 生物物理学
背景:
- 進化の偶然性を理解することは,進化生物学の鍵である.
- 実験的システムは,過去の進化的出来事に限られた洞察を与えます.
- 新しいタンパク質機能の進化は,しばしば歴史的な偶然の出来事に依存する.
研究 の 目的:
- 新しいタンパク質の機能のための代替的進化軌道を探求する.
- 祖先のタンパク質進化における許容性突然変異の希少性を調査する.
- 許容性突然変異の希少性の生体物理的根拠を決定する.
主な方法:
- 祖先のタンパク質の再構築
- 導かれた進化の実験
- タンパク質の多様性の生体物理分析
主要な成果:
- 祖先のグルココルチコイド受容体 (GR) 進化のための代替許容性突然変異は非常にまれでした.
- 歴史的な許容的置換は復元されたが,代替的な許容的遺伝子型は見つかりませんでした.
- 許容性突然変異は,局所構造の安定化,エネルギーバランスの維持,祖先および派生構造との互換性を要求する.
結論:
- 祖先のGRにおけるコルチゾール特異性の進化は,ありえない,非決定的イベントに強く依存していた.
- 許容性突然変異の希少性は,タンパク質の固有の生体物理特性から生じる.
- 進化の偶然性は,タンパク質の構造と機能に固有の生体物理的制約によって影響を受けます.
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