Researchers at the Helmholtz Institute for RNA-based Infection Research (HIRI) and the Julius-Maximilians-Universität Würzburg (JMU), together with colleagues from the Helmholtz Centre for Infection Research (HZI) in Braunschweig, have elucidated the mode of action of an important but previously uncharacterized anti-CRISPR protein.

Using a deep learning algorithm, they had previously discovered the protein called AcrVIB1, which acts against a nuclease that is used in research using CRISPR/Cas to deactivate genes by recognizing and cutting RNA. However, the way in which the new protein blocks this process was unknown.

Using cryo-electron microscopy, the researchers have now determined that the discovered protein inactivate the nuclease by binding to it, preventing the RNA from being degraded.

The scientists hope to be able to use the newly analyzed protein, called AcrVIB1, to regulate or temporarily disable CRISPR systems in various applications.

Original publication:
Wandera KG, Schmelz S, Migur A, Kibe A, Lukat P, Achmedov T, Caliskan N, Blankenfeldt W, Beisel CL: AcrVIB1 inhibits CRISPR-Cas13b immunity by promoting unproductive crRNA binding accessible to RNase attack. Molecular Cell (2025); DOI: 10.1016/j.molcel.2025.01.020.

Further source:
https://www.uni-wuerzburg.de/aktuelles/einblick/single/news/die-genschere-feinjustieren/