Over the past several years, CRISPR-Cas9 has moved beyond the lab bench and into the public zeitgeist. This gene-editing tool holds promise for correcting defects inside individual cells and potentially healing or preventing many human ailments. But the Cas9 system alters DNA, not RNA, and some experts believe that being able to modify RNA ultimately may prove just as useful.
Now scientists from the Salk Institute an independent, non-profit, scientific research institute in San Diego (USA), are reporting for the first time the detailed molecular structure of CRISPR-Cas13d, a promising enzyme for emerging RNA-editing technology. They were able to visualize the enzyme thanks to cryo-electron microscopy (cryo-EM), a cutting-edge technology that enables researchers to capture the structure of complex molecules in unprecedented detail.
The findings were recently published in Cell, a scientific journal publishing research papers across a broad range of disciplines within the life sciences. Derived from genes originally found in bacteria, CRISPR has been described as “molecular scissors” or a “word processing program for living cells.” It swaps out one segment of genetic code with another. In the CRISPR-Cas9 system, Cas9 is the enzyme that cuts DNA. Sulk Having editing tools for RNA, however, would allow scientists to modify a gene’s activity without making a permanent – and potentially dangerous – change to the gene itself.
The new study is built on the discovery of the Cas13d family and provides the molecular details that explain how it works. The team used cryo-EM to reveal new details into Cas13d by freezing the enzyme in different, dynamic states, allowing researchers to decode a range of activities instead of just seeing one activity at a single point in time.