Type V CRISPR/Cas systems

This table provided by Tong et al. (Front. Cell Dev. Biol. 8:622103) displays the properties of currently reported type V CRISPR/Cas systems. Because of trans cleavage activity, most of type V family effectors (Type V-K Cas12k excluded) are potential candidates as the toolbox of molecular diagnostics, including two popular ones, Cas12a and Cas12b. Note that the Type V-E Cas14 now has the new name of Cas12f.

However, more efforts should be put to address weak trans-cleavage activities possessed by some new Cas12 nucleases such as Cas12d, Cas14 (Cas12f), Cas12h, Cas12i and CasΦ (Cas12j).

Interestingly, Cas14 (Cas12f) has been expanded to cut dsDNA targets (Karveils et al. Nucleic Acids Research, 2020, 48(9).doi: 10.1093/nar/gkaa208) and thermostable Cas12a orthologs (CemCas12a and YemCas12a) have been mined (Fuchs et al. Communications Biology, 2022, 5:325). These examples indicate that “a huge treasure is buried in the mountain of Type V CRISPR/Cas systems”. How about V-M, N, L, and so on? Look at the map below. You’ll think more.