Engineered pistol ribozymes selectively target KRAS G12V with enhanced efficacy by capping modification.

In this study, we rationally engineered a previously characterized pistol ribozyme to selectively target the KRAS p.G12V mutation with high specificity and efficiency. The pseudoknot-induced compact folding structure of the pistol ribozyme provides three-dimensional structural recognition of the KRAS substrate, distinguishing it from siRNA and ASO, which rely solely on primary sequence complementarity. This structural advantage enables the designed pistol ribozyme to effectively differentiate between KRAS wild-type and G12V mutant RNA. Furthermore, compared with 3' end nucleotide derivative modifications, 5' end capping is more effective at increasing ribozyme stability and compatibility with in vitro preparations. These features underscore the promising potential of natural pistol ribozymes as advanced therapeutic nucleic acid molecules for targeting KRAS mutation-driven cancers and suggest a generalizable strategy for structure-guided, allele-specific RNA therapeutics.