Figure 1.

Overview and classification of the most common plasmid addiction systems (PAS) depending on their functionality and principle of mechanism. Toxin/antitoxin (TA) systems contain three separate subgroups with protein regulated loci, antisense RNA‐regulated mechanism or specific restriction modification. The general function of this group is illustrated above by the mechanism of TA systems. Metabolism‐based systems are divided into catabolism and anabolism‐based systems depending on their target pathway and complementation principle. The operator repressor titration (ORT) system is emphasized as a stand‐alone group.