New CRISPR-Cas system with on-off switch cuts proteins

Researchers from TU Delft in the group of Stan Brouns have discovered a CRISPR-Cas system that cuts proteins instead of DNA. The discovery opens the door to the development of a range of biotechnological and medical applications, for example for sensing RNA molecules in pathogens. Their research was published in Science yesterday. Researchers have been using CRISPR-Cas to precisely modify DNA for some years now, but bacteria have been using it for billions of years as an immune system against invading viruses. CRISPR-Cas proteins can cut the DNA of viruses and thereby render it harmless. But CRISPR-Cas now appears to go even further than cutting DNA. "When we discovered CRISPR-Cas, we observed that it cuts viral DNA in precise locations," explains Brouns.