A predicted immunity protein with an all alpha-helical fold and a conserved proline residue. Proteins containing this domain are present in bacterial polymorphic toxin systems as an immediate gene neighbour of the toxin gene, usually containing a domain of the Tox-REAse-1 or Tox-REase-6 families.
Jiyao W et al.(2023). "The conserved domain database in 2023.",