A predicted immunity protein with a mostly all-beta fold and a conserved arginine residue. Proteins containing this domain are present in bacterial polymorphic toxin systems as an immediate gene neighbour of the toxin gene, usually containing a Pput_2613 deaminase domain. The protein is also found in heterogeneous poly-immunity loci.
Jiyao W et al.(2023). "The conserved domain database in 2023.",