Engineer chimeric Cas9 to expand PAM recognition based on evolutionary information.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 30718489.
- Also identified by DOI 10.1038/s41467-019-08395-8 and PMC identifier 6361995.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Although Cas9 nucleases are remarkably diverse in microorganisms, the range of genomic sequences targetable by a CRISPR/Cas9 system is restricted by the requirement of a short protospacer adjacent motif (PAM) at the target site. Here, we generate a group of chimeric Cas9 (cCas9) variants by replacing the key region in the PAM interaction (PI) domain of Staphylococcus aureus Cas9 (SaCas9) with the corresponding region in a panel of SaCas9 orthologs. By using a functional assay at target sites with different nucleotide recombinations at PAM position 3-6, we identify several cCas9 variants with expanded recognition capability at NNVRRN, NNVACT, NNVATG, NNVATT, NNVGCT, NNVGTG, and NNVGTT PAM sequences. In summary, we provide a panel of cCas9 variants accessible up to 1/4 of all the possible genomic targets in mammalian cells.
Medical subject headings
- CRISPR-Associated Protein 9
- CRISPR-Cas Systems