Global Analysis of the Specificities and Targets of Endoribonucleases from Escherichia coli Toxin-Antitoxin Systems

Abstract

Toxin-antitoxin (TA) systems are widespread genetic modules found in almost all bacteria that can regulate their growth and may play prominent roles in phage defense. Escherichia coli encodes 11 TA systems in which the toxin is a known or predicted endoribonuclease. The targets and cleavage specificities of these endoribonucleases have remained largely uncharacterized, precluding an understanding of how each impacts cell growth and an assessment of whether they have distinct or overlapping targets.