Fig. 2
From: CRISPR-Cas, a robust gene-editing technology in the era of modern cancer immunotherapy
Schematic overview of the CRISPR-Cas9 complex and its mechanism of action in presence of target DNA. a Compartments of CRISPR-Cas9 complex bound to the target double-stranded DNA and sgRNA. Watson–Crick base pairing between target DNA and sgRNA leads Cas9 to the site of reaction. DNA DSB occurs at three nucleotides upstream of PAM motif (brown) by incorporation of HNH and RuvC domains. b Non-homologous end joining (NHEJ) repairing pathway and some of its consequences. NHEJ introduces indels (insertion/deletion) among target DNA and results in frameshift or loss of function inducement. c homology-directed repair (HDR) pathway and some of its after-effects. In presence of a donor template, which is flanked by sequences complement to target DNA, the reaction directs toward the HDR pathway, leading to precise insertion or edition