Reports from Chinese Academy of Sciences Highlight Recent Research in Engineering (Rapid characterization of anti-CRISPR proteins and optogenetically engineered variants using a versatile plasmid interference system).

Researchers from the Chinese Academy of Sciences have developed a versatile plasmid interference system that allows for the rapid characterization of anti-CRISPR proteins (Acrs) and the development of Acr-based technologies. The system was used to discover two novel Acrs, AcrIIA33 and AcrIIA34, which inhibit the activity of SpyCas9 by affecting DNA recognition. Additionally, the researchers created optogenetically engineered variants of the AcrIIA4 protein, called OPERA4, which can control the activity of SpyCas9 by approximately 1000-fold under switching dark-light conditions. The OPERA4 variants were found to achieve potent light-controllable genome editing in human cells as well. This work provides a versatile screening system for characterizing Acrs and developing controllable tools based on Acrs. [Extracted from the article]