Optimizing prime editing: Advances in efficiency enhancement

Prime editing (PE) enables the precise installation of targeted insertions, deletions, and all possible base-to-base conversions without introducing double-strand breaks or donor DNA templates. However, its efficiency remains highly variable across genomic contexts. To address this, multi-faceted optimization strategies have been developed: protein engineering has yielded editor variants with enhanced reverse transcriptase activity and stability; structural refinements to pegRNA design improve its functional integrity and resistance to degradation; regulation of the PE-Flap-mismatch repair (MMR) process favors the retention of desired edits; and the development of protospacer adjacent motif (PAM)-relaxed Cas variants dramatically expands targetable sites. This review systematically consolidates these advances, illustrating how the integration of structural, mechanistic and targeting enhancements is overcoming fundamental bottlenecks. Together, these developments establish PE as a versatile and efficient system for precision genome engineering, paving the way for its reliable application in diverse biological settings.