再プログラム可能なRNA標的型CRISPRシステムは,RNA毒素-抗毒素から進化した
Shai Zilberzwige-Tal1, Han Altae-Tran2, Soumya Kannan1
1Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research at MIT, Cambridge, MA 02139, USA; Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Cell
|February 19, 2025
まとめ
研究者は,RNAを標的とするCRISPR-Cas13システムの進化を追跡し,その起源は,中断感染 (AbiF) の毒素対抗毒素システムに由来する可能性があることを発見した. この研究は この進化的移行を可能にする 重要な構造的変化を明らかにしています
科学分野:
- 微生物学
- 分子生物学
- 進化生物学
背景:
- CRISPRシステムは,プロカリオットの適応免疫に不可欠です.
- RNA 誘導の CRISPR システム,特に Cas13 に繋がる進化の経路は完全に理解されていません.
- CRISPRの進化を理解することで ゲノム防衛機構の洞察が得られます
研究 の 目的:
- RNAを標的とする CRISPR-Cas13 システムの進化的祖先を特定する.
- Cas13eとAbiFとの関係を記述する.
- AbiFとCas13システムの構造と機能の違いを明らかにする.
主な方法:
- 統合された配列と構造の進化追跡
- Cas13eとAbiFの生化学的特徴
- AbiFの構造を決定するための冷凍電子顕微鏡 (冷凍EM).
主要な成果:
- Cas13システムはAbiFから進化した可能性があり,中断感染に関連した毒素-抗毒素システムです.
- Cas13eと呼ばれる小さなCas13は 進化の中間体として特定されました
- AbiFは,Cas13のRNA誘導RNAターゲティングとは異なるRNA抗毒素を伴う毒素対抗毒素システムとして機能する.
- AbiFの冷凍-EM構造は,Cas13sと比較して構造的な違いを示した.
- AbiFからCRISPRへの進化を促す 重要な構造的変化がマッピングされました
結論:
- この研究は,RNAを標的にするCRISPR-Cas13システムの明確な進化軌道を示しています.
- AbiFはCas13の前身であり,機能的および構造的移行を強調しています.
- この発見により プログラム可能な RNA 誘導システムの進化の理解が深まりました
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