The PAM Requirement and Expanding CRISPR Beyond SpCas9
Type
Blog Post
...These off-target sequences may be unintentionally mutated along with the desired target locus.
The PAM sequence...positive selection screens in bacteria to identify mutants of S. pyogenes Cas9 that were able to cleave target...PAM binding specificity:
SpCas9 variant
Mutations (relative to SpCas9)
PAM sequence
D1135E...human genome.
Another variant, xCas9 3.7 has 7 mutations found in the REC2, REC3, and PAM interacting domains...