Characterising a Novel HNH-Domain Containing Bacterial Immunity System From Escherichia coli

Abstract

Bacteria are constantly in danger of being attacked by bacterial viruses - bacteriophages. To combat the threat, bacteria have developed a wide array of intricate and diverse immune systems. Phage therapy’s growing popularity has led to increased interest in bacterial immunity. My thesis investigates one such potential immunity system from Escherichia coli, discovered by our colleagues at Lund University, named Bogomol. It is predicted to be comprised of an HNH-containing endonuclease domain and a C-terminal domain of unknown function. I validated Bogomol as an immunity system acting against certain phages of Straboviridae. This was done by performing efficiency of plating assays and liquid culture experiments against the BASEL phage library. As an attempt to further investigate the triggers of Bogomol, escape mutant experiments were also conducted.