Progress and prospects of engineered sequence-specific DNA modulating technologies for the management of liver diseases

Figure 3 Schematic representation of the clustered regularly interspaced palindromic repeats/clustered regularly interspaced palindromic repeats associated 9 complex and its interaction with DNA. With the CRISPR/Cas system, a 20 nucleotide guide RNA is processed and bound to the Cas9 protein. When adjacent to a proto-spacer–associated motif element, the guide recognises and binds a complementary sequence in the DNA to direct target cleavage by the Cas9 protein. A catalytically inactive Cas9 protein may also be coupled to other effectors such as Krüppel-associated box or VP16/64 domains. CRISPR/Cas: Clustered regularly interspaced palindromic repeats/CRISPR associated. CRISPR: Clustered regularly interspaced palindromic repeats; Cas: CRISPR associated; tracrRNA: Trans-activating CRISPR RNA; gRNA: RNA guide.