Cryo-EM structure of SAVED-Lon protease CCaCalpL filament bound to A4>p
要素
A4>p (5'-R(*AP*AP*AP*(A23))-3')
SMODS-associated and fused to various effectors domain-containing protein
キーワード
HYDROLASE / LON PROTEASE / SAVED DOMAIN / CRISPR
機能・相同性
SMODS-associated and fused to various effectors / SMODS-associated and fused to various effectors sensor domain / RNA / SMODS-associated and fused to various effectors domain-containing protein
ジャーナル: Mol Cell / 年: 2024 タイトル: Filament formation activates protease and ring nuclease activities of CRISPR Lon-SAVED. 著者: Dalia Smalakyte / Audrone Ruksenaite / Giedrius Sasnauskas / Giedre Tamulaitiene / Gintautas Tamulaitis 要旨: To combat phage infection, type III CRISPR-Cas systems utilize cyclic oligoadenylates (cA) signaling to activate various auxiliary effectors, including the CRISPR-associated Lon-SAVED protease CalpL, ...To combat phage infection, type III CRISPR-Cas systems utilize cyclic oligoadenylates (cA) signaling to activate various auxiliary effectors, including the CRISPR-associated Lon-SAVED protease CalpL, which forms a tripartite effector system together with an anti-σ factor, CalpT, and an ECF-like σ factor, CalpS. Here, we report the characterization of the Candidatus Cloacimonas acidaminovorans CalpL-CalpT-CalpS. We demonstrate that cA binding triggers CalpL filament formation and activates it to cleave CalpT within the CalpT-CalpS dimer. This cleavage exposes the CalpT C-degron, which targets it for further degradation by cellular proteases. Consequently, CalpS is released to bind to RNA polymerase, causing growth arrest in E. coli. Furthermore, the CalpL-CalpT-CalpS system is regulated by the SAVED domain of CalpL, which is a ring nuclease that cleaves cA in a sequential three-step mechanism. These findings provide key mechanistic details for the activation, proteolytic events, and regulation of the signaling cascade in the type III CRISPR-Cas immunity.
#181 - 2015年1月 カスケードとCRISPR (Cascade and CRISPR) 類似性 (1)
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集合体
登録構造単位
A: SMODS-associated and fused to various effectors domain-containing protein B: SMODS-associated and fused to various effectors domain-containing protein C: SMODS-associated and fused to various effectors domain-containing protein D: A4>p (5'-R(*AP*AP*AP*(A23))-3') E: A4>p (5'-R(*AP*AP*AP*(A23))-3')