Scientists continue to dig deeper into the Cas enzymes to further improve CRISPR-based genome editing technologies. A new addition to these enzymes is Cas14, which was discovered by researcher Lucas Harrington from University of California Berkeley and colleagues. 

In the study published in Science, the researchers describe the characteristics of Cas14 in terms of size, gene architecture, phylogeny, ability to associate with RNA components, ability to cleave DNA, and PAM requirement. Results showed that Cas14 is a small enzyme, which is half the size of previously known CRISPR RNA-guided enzymes. It was found to occur exclusively in a group of symbiotic archaea, the members of which have small genomes, and has similarities with previously characterized enzymes like C2c10 and C2c9. Cas14 is also able to perform programmable RNA-guided cleavage in the single-stranded DNA, making it the smallest known CRISPR enzyme that can do so. It also does not require a PAM sequence, a recognition site of most Cas enzymes, to function. Overall, the researchers discover 38 CRISPR-Cas14 systems that they grouped into families, namely, Cas14a to Cas14h. These systems may be used in studies that need targeting of single-stranded viruses.

For more information, read the article in Science.