Biochemists describe structure and function of newly discovered CRISPR immune system

Two seminal papers were published this week. The structure and function of the new CRISPR immune system is described in their findings.

Jackson is an assistant professor in Utah State University's Department of Chemistry and Biochemistry.

The USU researchers, along with colleagues from Germany's Helmholtz Institute forRNA-based Infection Research, U.S.-based biotechnology company Benson Hill and the University of Texas at Austin, report findings in tandem articles titled "Cas12a2 Elicits Abortive Infections via

The acronym "CRISP" has captured the imaginations of scientists and lay people alike, with its potential to modify genes. Although it's receiving a lot of attention for its gene-editing applications, the study of the genomes ofbacteria is still a young field and has yet to receive much attention. Researchers around the globe are trying to understand the basic structure of these systems.

Jackson says that the findings in the Nature papers were six years in the making.

Identified as a distinct immune system within the last five years, the Class 2, type VCas12a2 is somewhat similar to the better-known CRISPR-Cas9. The binding of the two genes has a very different effect.

Jackson says that theCas12a2Protein undergoes major conformational changes upon binding toRNA that open an indiscriminate site for DNA destruction. The cells that are destroyed byCas12a2 go senescent.

The USU team used "cryo-EM" to demonstrate the unique aspect of CRISPR-Cas12a2, including its degradation of single- and double-stranded genes.

Abortive infections are a natural strategy used bybacteria and archaea to limit the spread of Viruses and other pathogens A cell can be prevented from replicating by abortive infections.

Jackson says the team cut double-stranded DNA in order to capture the structure of Cas 12a2.

He says that the nucleases bend the normally straight piece of double-helical DNA 90 degrees to force it into the active site. It's a change in structure that makes other scientists gasp.

Jackson says that the difference between a healthy cell and a cancer-causing cell is genetics.

The potential therapeutic applications are significant if it is possible to identify, target and destroy cells at the genetic level.

Efforts to stem the effects of a number of genetic diseases could be aided by the information contained in the set of papers.

Jackson says that they believe that Cas 12a2 could lead to improved and additional CRISPR technologies that will benefit society.

There is more information about Dymtrenko. Nature reported on "Cas12a2 Elicits Abortive Infections viaRNA-triggered Destruction of dsDNA." The article can be found at www.nature.com.

Jack and the others. Nature published a story titled "RNA Targeting Unleashes Indiscriminate Nuclease Activity of CRISPR-Cas12a2". The article can be found at www.nature.com.

Journal information: Nature