Asymmetric degradation bottleneck and pegRNA half‑life limitation in prime editing Prime editors (PE) enable precise base substitution, insertion, and deletion without double‑strand breaks (DSB) or donor DNA templates, representing the pinnacle of next‑generation genomic medicine. However, the most critical weakness in clinical and pre‑clinical pipelines is an extremely low editing efficiency (transduction bottleneck). At the core of this barrier is the 3′ extension of the prime editing guide RNA (pegRNA), which, due to its complex structure, is exposed to intracellular exonucleases and is degraded in real time before it can bind the editor protein complex, imposing a kinetic limitation. When the guide is cleaved, the reverse‑transcriptase domain cannot function, limiting the final genotype fixation rate.

Establishment of an optimized artificial motif architecture through directed‑evolution screening The study, published in Nature Biotechnology on May 20, introduced a materials‑engineering solution that shields the structural Achilles’ heel of pegRNA. The authors constructed a library of millions of synthetic RNA sequences and employed a rapid directed‑evolution pipeline to select higher‑order structures that survive intracellular nuclease stress. This screening identified an engineered RNA‑stabilizing motif that fuses perfectly to the 3′ terminus of pegRNA, creating a strong steric hindrance that acts as a shield, dramatically extending the guide RNA half‑life within the capsid and cytoplasm.

Explosive >200 % increase in genome‑editing efficiency and control of off‑target noise When the next‑generation PE system equipped with the stabilizing motif was delivered to high‑complexity disease‑model cell lines, precise correction efficiency on target loci more than doubled relative to standard protocols. Molecular dynamics analysis demonstrated that the prolonged intracellular survival of pegRNA provides a “golden time” for a single editor complex to locate the target DNA and complete the prime reverse‑transcription (extension‑annealing) reaction. High editing rates were achieved without excess editor protein, and off‑target genotoxicity was reduced to baseline, demonstrating overwhelming safety.

Establishment of a programmable RNA‑stabilization backbone and acceleration of platform gene‑design The structural‑genomics data deliver a standardized plug‑in backbone sequence that prevents guide RNA degradation. This artificial motif constitutes a universal hardware layer that can be grafted onto any small RNA‑based therapeutic modality—base editors, CRISPRa/i, mRNA therapeutics, etc.—to tune half‑life. Integration of this plug‑in into the BioArx platform’s guide‑RNA design module will enable virtual prediction of intracellular mRNA/ncRNA half‑life and editing efficiency, dramatically lowering the required physical dose of molecular scissors while maximizing effective correction rates, creating a unique artificial genome‑engineering asset.