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ヘモグロビンの進化における複雑性の起源
Arvind S Pillai1, Shane A Chandler2, Yang Liu3
1Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA.
Nature
|May 29, 2020
まとめ
現代のヘモグロビンは 古代の単一タンパク質から進化しました 遺伝子の複製と 重要な変異が 複雑な構造と 協力的な酸素結合を 作り出したことを明らかにしました
科学分野:
- 進化生物学
- 分子生物学
- 生物化学
背景:
- タンパク質は複合的な構造 (マルチマー) を形成し,協同リガンド結合のような特殊な機能を持つ.
- これらの複雑なタンパク質の構造と機能の 進化的起源は ほとんど知られていません
- 脊椎動物のヘモグロビンはテトラマーで 協同結合によって酸素を輸送する.
研究 の 目的:
- 脊椎動物のヘモグロビンの進化的起源を明らかにする
- 祖先のタンパク質構造と 進化の中間物質を特定する
- 複雑なタンパク質の機能の進化を促す 遺伝的・生体学的メカニズムを理解する
主な方法:
- 祖先のタンパク質の再構築
- 生物物理的測定法
- 比較ゲノミクス
主要な成果:
- 現代ヘモグロビンは 古代のモノマーから進化しました
- 高酸素親和性を持つ非協力性ホモディマーが重要な進化的中間体として特定された.
- 2つの特定の変異は,祖先のタンパク質にテトラメリゼーションと協力的な酸素結合を誘導するのに十分であった.
- 酸素結合とマルチメリゼーションのインターフェースの間の本質的なリンクは,祖先の構造に存在していました.
結論:
- 複雑なタンパク質の構造と機能は 単純な遺伝的変化によって進化します
- 進化は,既存の生体物理的特性を再利用して,より高いレベルの分子構造を作り出すことができます.
- ヘモグロビンの進化は,モノマーから機能的なテトラマーへの段階的なプロセスを示しています.
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