THOERIS – A BACTERIAL DEFENSE SYSTEM CONTAINING TIR-DOMAIN PROTEINS

Bacteria utilize multiple sophisticated molecular systems for defense against phages. A recent discovery project identified 10 new defense systems that protect bacteria against phages and plasmids through yet unknown mechanisms of action [1]. Among them, we identified a system encoding TIR domain-containing proteins that provides defense against phage infection. The TIR domain is a canonical component of innate immunity systems of invertebrates, vertebrates and plants, where it serves mainly as a signal transduction domain of Toll-like receptors. The involvement of TIR domains in bacterial immunity against phages suggests an ancient and common role of this domain in immunity across all domains of life.

[1] Shany Doron, Sarah Melamed, Gal Ofir, Azita Leavitt, Anna Lopatina, Mai Keren, Gil Amitai, and Rotem Sorek. "Systematic discovery of antiphage defense systems in the microbial pangenome." Science 359, no. 6379 (2018): eaar4120.