A predicted toxin domain found in bacterial polymorphic toxin systems. The toxin possesses an alpha+beta fold with a conserved glutamine residue and a [KR]STxxPxxDxx[ST] motif. In bacterial polymorphic toxin systems, the toxin is exported by the type 2 or type 6 secretion system [1].

1: Polymorphic toxin systems: comprehensive characterization of trafficking modes, processing, mechanisms of action, immunity and ecology using comparative genomics. Zhang D, de Souza RF, Anantharaman V, Iyer LM, Aravind L; Biol Direct. 2012;7:18. PMID:22731697