タイプVのCRISPRトランポゾンシステムによる標的部位の選択と再構成
Irma Querques1, Michael Schmitz1, Seraina Oberli1
1Department of Biochemistry, University of Zurich, Zurich, Switzerland.
Nature
|November 11, 2021
まとめ
研究者はCRISPR関連トランポゾンによるRNA誘導DNAトランポシションのメカニズムを明らかにした. 構造と生化学の研究は Cas12k が DNA 挿入をどのように誘導し,新しい遺伝子編集ツールを可能にすることを示しています.
科学分野:
- 分子生物学
- 遺伝学
- 生物化学
背景:
- CRISPR-Casシステムは 移動性遺伝子要素に対する 適応性免疫を提供します
- Tn7型トランポゾンは,RNA誘導DNA挿入のためにCRISPRシステム (タイプI-F,I-B,V-K) を利用する.
- V-K型CRISPR関連トランポゾンによるRNA誘導DNAトランポシションの分子メカニズムは不明である.
研究 の 目的:
- V-K型CRISPR関連トランポゾンによるRNA誘導DNAトランポシションの分子メカニズムを解明する.
- Cas12kガイドRNA複合体による標的DNA認識の構造的基礎を決定する.
- TnsC,TnsB,TniQの役割を理解する
主な方法:
- 低温電子顕微鏡 (cryo-EM) で,Cas12kガイドRNA標的DNA複合体とDNAに結合したTnsCフィラメントの構造を決定する.
- 構造的な発見を検証するために,in vivoトランスポーゼーションアッセイ
- タンパク質の相互作用と酵素の活性を調べる生化学実験
主要な成果:
- Cryo-EM構造は,複雑なガイドRNAアーキテクチャと,Cas12kによるRNA誘導DNA認識のための重要な相互作用を明らかにした.
- TnsCフィラメントはATPに依存し,DNAの二重再構成を誘導する.
- TniQはTnsCのポリメリゼーションを制限し,TnsBはATPの水解によってTnsCのフィラメントの分解を誘発し,トランポゾン挿入を容易にする.
結論:
- Cas12kによるRNA誘導の標的選択は,TnsCのポリメリゼーションとDNAの改造を開始する.
- このプロセスは,TnsBがサイト固有のトランポゾン挿入を触媒化するプラットフォームを作成します.
- 研究結果は,プログラム可能な遺伝子挿入ツールとしてCRISPR関連トランポゾンを開発するための洞察を提供します.
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