Ribonucleases in bacterial toxin-antitoxin systems

► The most common target of toxin-antitoxin (TA) systems in microorganisms is mRNA. ► The toxin components that cleave cellular mRNA have been termed RNA interferases. ► RNA interferases are sequence-specific endoribonucleases that cleave RNA. ► RNA interferases have been implicated in a number of important cellular processes in bacteria.