The ongoing bacterial-viral arms race fuels the continuous evolution of phage attack and bacterial defense mechanisms. Bacterial defenses employ various strategies, with the most prevalent targeting and degrading phage nucleic acids. These defenses include restriction-modification (RM) systems, CRISPR-Cas systems, prokaryotic Argonautes (pAgo). Abortive infection systems act differently, killing the cell upon recognizing phage infection to prevent spread to neighboring cells and protect the bacterial community. Some recent antiviral mechanisms directly inhibit phage DNA and RNA synthesis, like prokaryotic viperins (pVips) producing RNA chain terminator molecules.
In recent years, numerous bacterial anti-phage defense systems with unknown defense mechanisms have been identified (Vassallo Nature Microbiology; Altae-Tran 2023 Science; Payne 2024 Biorxiv). Associated with known defense systems in defense islands, these systems have experimentally proven their efficacy against phages. Future studies aim to unveil the mechanisms of these new systems. During PhD, biochemical and biophysical methods will be employed to study mechanisms of a chosen bacterial antiviral defense system. We have used these methods successfully in studying the mechanism of Type III CRISPR-Cas (Kazlauskiene Science 2017; Smalakyte 2020 Nucleic Acids Research; Mogila Science, 2023). The VU Life Science Center is well-equipped for these anticipated studies.