Year: 2025
Type: article
Abstract: Two recent cryo-electron microscopy (cryo-EM) studies have captured the HNH domain's ability to replace Cas3 within the Cascade complex (CRISPR-associated complex for antiviral defense) in both type I-E and type I-F CRISPR-Cas systems.1,2 These findings reveal that Cas3 is not required and the HNH domain forms a ring-like structure with Cascade, enabling precise DNA cleavage and providing a new avenue for understanding bacterial CRISPR-Cas immune responses.CRISPR-Cas systems, which stand for Clustered Regularly Interspaced Short Palindromic Repeats and CRISPRassociated genes, are adaptive immunity mechanisms in bacteria and archaea, designed responsible for protecting against viral invasion.The immune response typically involves three stages: adaptation, expression, and interference.Based on the Cas effectors used during CRISPR interference, these systems are categorized into two classes and seven types.Class 1, including types I, III, IV, and VII, comprises multi-subunit Cas protein effector complexes, whereas Class 2, which includes types II, V, and VI, is composed of single-subunit Cas protein effectors.3,4 In canonical type I systems, multiple Cas proteins assemble into a crRNA-containing Cascade complex, which stands for CRISPR-associated complex for antivi-# Senfeng Zhang and Yao Liu contributed equally.
Source: MedComm
DOI: 10.1002/mco2.70060
Authors: Senfeng Zhang, Yao Liu, Chunyi Hu
Institution: National University of Singapore
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,500
Award: G2218048904
OpenAlex ID: W4407544902