Genomic double-stranded DNA (CRISPR target site) (dsDNA)

Genomic double-stranded DNA (dsDNA) at sequences complementary to a single-guide RNA (sgRNA) spacer, located adjacent to a Protospacer Adjacent Motif (PAM), serves as the primary molecular target for CRISPR-Cas-based gene editing technologies (Jinek et al., 2012, Science). In this system, a Cas nuclease is guided to a specific genomic locus by the sgRNA, which hybridizes with the target DNA strand through complementary base pairing (Doudna & Charpentier, 2014, Science). The presence of a PAM sequence is essential for the initial binding and subsequent cleavage of the DNA by the nuclease domains (Sternberg et al., 2014, Nature). This interaction allows for precise genome modifications, including gene knockout via non-homologous end joining or gene correction via homology-directed repair (Hsu et al., 2014, Cell). Therapeutically, this target is utilized to treat genetic disorders by disrupting pathogenic genes or restoring functional protein expression, as seen in the FDA-approved therapy exagamglogene autotemcel for sickle cell disease (FDA, 2023). However, the potential for off-target activity at similar DNA sequences remains a significant safety concern and a focus of clinical monitoring (Fu et al., 2013, Nature Biotechnology).

Other names

CRISPR target sequenceProtospacerPAM-adjacent DNAsgRNA-complementary DNATarget DNA locus

Site-specific DNA cleavage or chemical modification initiated by RNA-guided hybridization and Protospacer Adjacent Motif (PAM) recognition, leading to endogenous DNA repair or base conversion.