A predicted immunity protein with an alpha+beta fold and a conserved E+G and ExxY motifs. Proteins containing this domain are present in bacterial polymorphic toxin systems as an immediate gene neighbour of the toxin gene, which usually contains toxin domains of the Ntox40, Tox-CdiAC and Tox-ARC families [1]. The protein is also found in poly-immunity loci in polymorphic toxin systems.

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