Fig. 1
From: Type II CRISPR/Cas9 approach in the oncological therapy
Type II CRISPR mechanism of action. Foreign DNA is cut and acquired by Cas1 and 2 between CRISPR repeat sequences (a) forming PAMs. Then a RNA Polymerase transcribes part of the CRISPR repeat and part of the PAM generating a crRNA (b) that hybridize with a tracrRNA and reach a homologous target sequence on the genomic DNA (c). Cas9 performs a DSB that it is repaired with a NHEJ causing indel mutations and so probably a premature stop codon (d)