Cas12a

Cas12a (CRISPR associated protein 12a, previously known as Cpf1) is a subtype of Cas12 proteins and an RNA-guided endonuclease that forms part of the CRISPR system in some bacteria and archaea. It originates as part of a bacterial immune mechanism, where it serves to destroy the genetic material of viruses and thus protect the cell and colony from viral infection. Cas12a and other CRISPR associated endonucleases use an RNA (termed a crRNA in the case of Cas12a) to target nucleic acid in a specific and programmable matter. In the organisms from which it originates, this guide RNA is a copy of a piece of foreign nucleic acid (i.e. phage) that previously infected the cell.

It is of interest to researchers because it can be used to make highly targeted modifications of DNA or RNA, similar to the better known CRISPR-Cas9 system. Cas12a is distinguished from Cas9 by a its single RuvC endonuclease active site, its 5' protospacer adjacent motif preference, and for creating sticky rather than blunt ends at the cut site. These and other differences may make it more suitable in certain applications. Beyond its use in basic research, CRISPR-Cas12a could have applications in the treatment of genetic illnesses and in implementing gene drives.