Download MendeleyStructural basis of negative regulation of CRISPR-Cas7-11 by TPR-CHAT.
Hong, T., Luo, Q., Ma, H., Wang, X., Li, X., Shen, C., Pang, J., Wang, Y., Chen, Y., Zhang, C., Su, Z., Dong, H., Tang, X.(2024) Signal Transduct Target Ther 9: 111-111
- PubMed: 38735995
- DOI: https://doi.org/10.1038/s41392-024-01821-4
- Primary Citation of Related Structures:
8WM4, 8WMC, 8WMI, 8WML - PubMed Abstract:
CRISPR‒Cas7-11 is a Type III-E CRISPR-associated nuclease that functions as a potent RNA editing tool. Tetratrico-peptide repeat fused with Cas/HEF1-associated signal transducer (TPR-CHAT) acts as a regulatory protein that interacts with CRISPR RNA (crRNA)-bound Cas7-11 to form a CRISPR-guided caspase complex (Craspase). However, the precise modulation of Cas7-11's nuclease activity by TPR-CHAT to enhance its utility requires further study. Here, we report cryo-electron microscopy (cryo-EM) structures of Desulfonema ishimotonii (Di) Cas7-11-crRNA, complexed with or without the full length or the N-terminus of TPR-CHAT. These structures unveil the molecular features of the Craspase complex. Structural analysis, combined with in vitro nuclease assay and electrophoretic mobility shift assay, reveals that DiTPR-CHAT negatively regulates the activity of DiCas7-11 by preventing target RNA from binding through the N-terminal 65 amino acids of DiTPR-CHAT (DiTPR-CHAT NTD ). Our work demonstrates that DiTPR-CHAT NTD can function as a small unit of DiCas7-11 regulator, potentially enabling safe applications to prevent overcutting and off-target effects of the CRISPR‒Cas7-11 system.
Organizational Affiliation:
Department of Laboratory Medicine, State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China.
