Anti-CRISPRs
“CRISPR–Cas adaptive immune systems are widespread among bacteria and archaea. This suggests that the ability to evade CRISPR–Cas immunity must also be widespread in phages and other mobile genetic elements”
Studies of the evolutionary arms race fought between bacteriophages and bacteria have led to the development of many useful biotechnological tools. CRISPR-Cas gene editing is one such technology that has revolutionized scientific research. In nature, CRISPR-Cas is an adaptive immune system found in many bacterial species that protect against phages. In collaboration with Alan Davidson's lab, we discovered that phages have evolved a means to evade this immune system by utilizing small proteins that shut down CRISPR-Cas machinery. These “anti-CRISPR” proteins were found to be widespread in nature, encoded by many different phages and inhibiting various types of CRISPR-Cas systems.
Work in our lab is focused on the discovery and characterization of anti-CRISPRs that target the type II CRISPR-Cas9 systems found in bacteria like Neisseria meningitidis and Haemophilus parainfluenzae. We utilize bioinformatics and genetic screens to identify new anti-CRISPRs, and we characterize them using a combination of biological, biochemical and biophysical techniques.