Scientists delineate molecular details of a new bacterial CRISPR-Cpf1 system and open possible avenue for alternative gene editing uses like targeting several genes in parallel
Only a few years after its discovery, it is difficult to conceive of genetics without the CRISPR-Cas9 enzyme scissors, which allow for a very simple, versatile and reliable modification of DNA of various organisms. Since its discovery, scientists throughout the world have been working on ways of further improving or adjusting the CRISPR-Cas9 system to their specific needs.
Researchers from the Max Planck Institute for Infection Biology in Berlin, the Umeå University in Sweden and the Helmholtz Centre for Infection Research in Braunschweig have now discovered a feature of the CRISPR-associated protein Cpf1 that has previously not been observed in this family of enzymes: Cpf1 exhibits dual, RNA and DNA, cleavage activity. In contrast to CRISPR-Cas9, Cpf1 is able to process the pre-crRNA on its own, and then using the processed RNA to specifically target and cut DNA. Not requiring a host derived RNase and the tracrRNA makes this the most minimalistic CRISPR immune system known to date.
The mechanism of combining two separate catalytic moieties in one allows for possible new avenues for sequence specific genome engineering, most importantly facilitation of targeting multiple sites at once, the so-called multiplexing.
CRISPR-Cas is part of the immune system of bacteria and is used to fight viruses. In the CRISPR-Cas9 system, the enzyme Cas9 cuts the virus DNA at a location specified by an RNA molecule – known as CRISPR RNA (crRNA) in complex with another RNA, the so-called tracrRNA. This puts the pathogens out of action.