FLICKR, NIH IMAGE GALLERYMuch attention paid to the bacterial CRISPR/Cas9 system has focused on its uses as a gene-editing tool. But there are other CRISPR/Cas sytems. Researchers from MIT and the National Center for Biotechnology Information (NCBI) last year identified additional CRISPR proteins. One of these proteins, C2c2, seemed to be a putative RNA-cleaving—rather than a DNA-targeting—enzyme, the researchers reported at the time. Now, the same group has established that C2c2 indeed cleaves single-stranded RNA (ssRNA), providing the first example of a CRISPR/Cas system that exclusively targets RNA. The team’s latest results, published today (June 2) in Science, confirm the diversity of CRISPR systems and point to the possibility of precise in vivo RNA editing.
“This protein does what we expected, performing RNA-guided cleavage of cognate RNA with high specificity, and can be programmed to cleave any RNA at will,” study coauthor Eugene Koonin, of the NCBI and the National Library of Medicine, told The Scientist.
“I am very excited about the paper,” said Gene Yeo, an RNA researcher at the University of California, San Diego, who was not involved in the work. “The community was expecting to find native RNA CRISPR systems, so it’s great that one of these has now been characterized.”
The researchers originally identified C2c2 in Leptotrichia shahii in a systematic search for previously unidentified CRISPR systems within diverse bacterial genomes. For the present study, the team focused on C2c2, as its sequence contained two copies ...
