Tiny CRISPR Tool to Fight Viruses Through an RNA-targeting System

Researchers from Rice University described one of the smallest known CRISPR-Cas13 systems, CRISPR-Cas13bt3, in a three-dimensional structure. The researchers hope this could combat viruses by targeting RNA, which generally encode their genetic information using RNA rather than DNA.

Cas13 is commonly used for in vivo RNA knockdown and transcriptome modulation because of its high precision in targeting RNA. However, the large size of Cas13 effectors, which contains 967-1152 amino acids, hinders the adeno-associated virus-based delivery of Cas13 systems for therapeutic applications. Hence, this study described a smaller Cas13 molecule called Cas13bt3 with about 700 amino acids. A cryo-electron microscope was used to map the structure of the CRISPR system.

Yang Gao, an assistant professor of Biosciences and Cancer Prevention and Research Institute of Texas Scholar, said this system is different from other proteins in the Cas13 family. Unlike the other proteins, “the scissor is already there, but it needs to hook onto the RNA strand at the right target site,” Gao said. The findings of the study also provided detailed structural biology insights that could help future research to improve the tool's precision without compromising its high accuracy in editing RNA.

For more information, read the article from Nature Communications.