Kinetic basis for Cas12a off-target discrimination.

ABSTRACT: CRISPR-Cas12a proteins are RNA-guided endonucleases classified as type V-A effectors that function similarly to Cas9, but possess distinct biochemical features. Previous studies have reported that compared to Cas9, Cas12a exhibits reduced off-target activity, yet the mechanistic origin of this high specificity remains unclear. In this study, we used singlemolecule fluorescence assays to investigate the kinetic basis for the reduced off-target effects of Cas12a. Introducing double mismatches at various positions within the target DNA enabled systematic analysis of the off-target effects on individual reaction steps in the Cas12a-mediated DNA cleavage reaction: seeding, stable R-loop formation, and DNA cleavage. Our results show that mismatches within a 17 bp PAM-proximal seed region signifi

SUBMITTER: Kim Y 

PROVIDER: S-EPMC12402690 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature