
Cap 1 N1meψ PEmax-P2A-EGFP mRNA
PEmax is an innovative advancement in PE4 and PE5 prime editing systems that addresses cellular barriers to precise DNA alterations. In the PE2 and PE3 systems, DNA mismatch repair (MMR) hinders prime editing and promotes unwanted indel byproducts. To counteract this, PE4 and PE5 prime editing systems, in which transient expression of an engineered MMR-inhibiting protein enhances the efficiency of substitution, small insertion, and small deletion prime edits by an average of 7.7-fold and 2.0-fold compared to PE2 and PE3 systems, respectively, while improving edit/indel ratios by 3.4-fold in MMR-proficient cell types. This mRNA possesses a Cap1 structure, which is highly efficient in capping. It is fully substituted with N1-methyl-pseudo Uridine to improve expression and decrease immunogenicity. Additionally, the mRNA features a 110A tail in its sequence, resembling a mature mRNA.