Genomic DNA sequence complementary to the Cas12n guide RNA (Cas12n target DNA)

The genomic DNA sequence complementary to the Cas12n guide RNA is the specific chromosomal locus targeted for modification by the Cas12n CRISPR-Cas system. Cas12n refers to a class of miniature Type V CRISPR effectors that are significantly smaller than traditional Cas9 or Cas12a proteins, making them ideal for delivery via size-constrained viral vectors like adeno-associated virus (AAV) [1, 3]. This DNA sequence, often called the protospacer, is recognized through Watson-Crick base pairing with the spacer region of the CRISPR RNA (crRNA) [2]. For successful binding and cleavage, the target sequence must be immediately adjacent to a specific nucleotide motif known as the protospacer adjacent motif (PAM) [1]. Once the Cas12n-crRNA complex binds to this target, the enzyme's RuvC nuclease domain induces a site-specific break in the DNA [3]. This mechanism is utilized in therapeutic contexts to disrupt pathogenic genes, correct mutations, or regulate gene expression in various genetic disorders and cancers [4]. However, the primary challenge in targeting these sequences is the risk of off-target activity, where the enzyme binds and cleaves similar sequences elsewhere in the genome, potentially leading to unintended mutations or genomic instability [5].

Other names

ProtospacerCas12n target siteCas12n-complementary DNA sequenceCRISPR-Cas12n target sequence

RNA-guided DNA binding and site-specific endonuclease activity leading to double-strand breaks or nicks.