Characterization and engineering of a type IV-A3 CRISPR-Cas system for genome editing in Escherichia coli.

ABSTRACT: CRISPR-Cas systems have revolutionized genome engineering technologies, but type IV CRISPR-Cas systems and their genome engineering potential have been critically underexplored. In this study, we identified a type IV-A3 CRISPR-Cas system from a clinical Klebsiella pneumoniae isolate and characterized its plasmid targeting activity and capacity to suppress chromosomal and plasmid gene expression in Escherichia coli. We revealed the pivotal role of Csf3 (Cas5) and the dispensable roles of Csf1 (Cas8-like) and Csf4 (DinG helicase) subunits in IV-A3 CRISPR-Cas complex formation. The system prevents plasmid propagation via interplay between DinG helicase activity and strategic protospacer positioning relative to plasmid replication and maintenance components. We enabled the IV-A3 CRISPR-Cas sys

SUBMITTER: Semsey S 

PROVIDER: S-EPMC12714566 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature