Laredo, Texas – Scientists at the University of Texas at Austin have redesigned a key component of a Crispr-based gene-editing tool; Thanks to its ability to destroy genetic material, the discovery could lead to the development of new cheap and highly sensitive home diagnostic tests for a wide range of infectious diseases such as COVID-19, flu, Ebola and Zika . Author of the study published in the scientific journal nature,
CRISP is the hallmark of a bacterial defense system that forms the basis of the widely used CRISPR-Cas9 genome-editing technology, as it acts as a type of polyvalent self-destruct system for bacteria, which can react with a single -stranded RNA, capable of degrading single- stranded DNA and double stranded DNA.
Using a high-resolution imaging technique called cryo-EM, the team of experts found that when this protein binds to a specific sequence of genetic material from a potentially dangerous virus, called a target RNA, one of CAS12A2 The part is displaced outward so as to reveal a. The active site functions similarly to an open snap razor.
After that, the active site begins to indiscriminately cut any type of genetic material with which it comes into contact. In this way, with a single mutation in the Cas12a2 protein, the active site degrades only single-stranded DNA, a feature particularly useful in the development of new diagnostics suited to a wide range of viruses.
In principle, a test based on this technology could combine the best features of PCR-based tests that detect genetic material from viruses with the best features of rapid home diagnostic tests.
“If a new virus comes out tomorrow, all you have to do is find its genome and then change the guide RNA in your test, and you have a test against it,” says an associate professor of molecular biosciences. David Taylor said. at the University of Texas at Austin and co-author of the new study.
This discovery has yet to be tested, however it is a breakthrough and could help develop more efficient tests.
“Cas12a2 basically grabs the two ends of the DNA double helix and folds them very tightly. So the helix in the middle opens up, and then it allows this active site to destroy the piece of DNA that is single-stranded.” This is what sets Cas12a2 apart from all other DNA-targeting systems,” said Jack Bravo, postdoctoral fellow at UT Austin and co-author of the paper.
Structural data were collected using the cryo-EM facility at the Sawyer Structural Biology Laboratory at The University of Texas at Austin.
The paper is co-authored by Ryan Jackson and co-authored by Thomson Hallmark, both from Utah State University. Other co-authors are Bronson Naegel and Helmholtz Center for Infection Research from Utah State and Chase Bessel from the University of Würzburg in Germany.