Accepted_test

Evolution and distribution of prokaryotic type III toxin-antitoxin systems
by Igor Selifonov | Denis Moshenskiy | Andrey Alekseevskiy | A. N. Belozersky Institute of Physico-Chemical Biology | A. N. Belozersky Institute of Physico-Chemical Biology | A. N. Belozersky Institute of Physico-Chemical Biology
Abstract ID: 634
Event: BGRS-abstracts
Sections: [Sym 5] Section “Molecular phylogenetics and phylogenomics of Plants, Fungi, Protists, Prokaryotes and Viruses”

Type III toxin-antitoxin (TA) systems consist of a protein toxin and a small pseudoknot RNA antitoxin. The latest thorough bioinformatic analysis of these systems was performed by Blower et al. in 2012. In this work we revisit this topic with new genomic data. Using HMM profiles created for the 3 families of type III TA systems, we identified and classified 610 putative TA loci in prokaryotic genomes. The newly described type III TA systems displayed an uneven phylogenetic distribution. We then compared the evolutionary trees created for unique toxin sequences with the trees built based on a set of essential proteins of the corresponding organisms. This analysis showed that horizontal gene transfer between both closely related and distant groups of prokaryotes plays a significant role in the evolution and spread of type III TA systems.