Figure 5.

Prime editing mechanism: a) Nicking the desired DNA sequence at the PAM strand by the fusion protein, b) the exposed 3ʹ-hydroxyl group prime the reverse transcription of the RT template of the pegRNA, c) reverse transcription, d) the branched intermediate form containing two flaps of DNA: a 3ʹ flap (containing the edited sequence), and a 5ʹ flap (containing the dispensable, unedited DNA sequence) followed by flap cleavage, and e) ligation and mismatch repair; either the incorporating edite strand or remove it.