SaCas9

SaCas9 is an RNA-guided DNA endonuclease derived from the CRISPR-Cas system of Staphylococcus aureus. Guided by a single-guide RNA (sgRNA), it recognizes target DNA sequences adjacent to a 5'-NNGRRT-3' PAM and introduces site-specific double-strand breaks through its HNH and RuvC nuclease domains. At approximately 3.2 kb, SaCas9 is substantially smaller than SpCas9, enabling efficient packaging into adeno-associated virus (AAV) vectors for in vivo genome editing. Its compact size and robust editing activity make SaCas9 a valuable biomodule for therapeutic genome engineering and synthetic biology applications.