xCas9: Engineering a CRISPR Variant with PAM Flexibility
Type
Blog Post
Published
March 28, 2018, 6:52 p.m.
...work, there are other options. Commonly used Cpf1 variants, with a 5’ TTTV PAM, improve targeting in AT-...respectively. Researchers also engineered SpCas9 variants with alternative PAMs like NGAG and NGCG and SaCas9... in the pool. According to this logic, ω-dCas9 variants recognizing multiple PAMs should have a fitness...promoting survival of only the broadest-targeting variants. For the final round of evolution, they used a... a no-G PAM library to enrich for Cas9 variants with activity on non-NGG PAMs, generating xCas9 3.0-3.13...rate as SpCas9 at an NGG PAM. When they tested a variety of NG, GAT, GAA, and CAA PAMs, they saw that xCas9...confirming the flexibility of xCas9 3.7.
Base editor variants with xCas9 are similarly flexible. Like the xCas9...