Phylogenetic Analysis of Type II Toxin-Antitoxin Systems
Physical and Biological Sciences
METX Independent Study
Recent studies have highlighted the incredible specificity of toxin-antitoxin type II (TA) systems in bacteria. These toxic pairs have been implicated in virulence and plasmid maintenance. TA systems consist of a toxin protein and a corresponding antitoxin protein that binds to the toxin to inhibit it. The toxin targets essential bacterial machinery such as growth and replication factors. Due to their toxic nature, they are highly specific pairs where the antitoxin cannot act on another of a similar species. Emerging evidence suggests that multiple antitoxin species can bind to the same toxin. This challenges the traditional 1:1 genetic specificity relationship of TA systems therefore prompting a re-evaluation of TA system classification, specifically in Type II TA systems. This paper will present findings from phylogenetic analyses to understand this phenomenon of multiple antitoxin families binding to the same toxin family and its implications for classifying Type II TA systems.
