Search-and-replace genome editing The prime editor complex includes An engineered "pegRNA" a Cas9 enzyme,modified to only Iprime editing guide RNA] nick one strand of DNA,and a sends the editor to its target. reverse transcriptase enzyme, where Cas9 nicks the DNA. which can generate new DNA by copying an RNA template. pegRNA Reverse Cas9 transcriptase Cas9 Nicks one R strand of DNA The pegRNA has two special To transfer the edited sequence components:a section that binds from the pegRNA to the target to the nicked DNA,preparing DNA.the reverse transcriptase the nicked strand to have new reads the RNA and attaches the DNA letters added,and a section corresponding DNA letters to the of RNA letters that encode the end of the nicked DNA. desired edit. Edited RT sequence Binding Edited region sequence Binding region New DNA 而u证