The DNase toxin domain called PoNe (Polymorphic Nuclease effector) belongs to a diverse superfamily of PD-(D/E)xK phosphodiesterases, and is associated with several toxin delivery systems including type V, type VI, and type VII. PoNe toxicity is antagonized by cognate immunity proteins (PoNi) containing DUF1911 and DUF1910 domains. This subfamily contains proteins with PoNe domains that typically co-occur with N-terminal hemagglutinin repeats and/or a hemagglutination activity domain.