A predicted toxin of the ADP-ribosyltransferase superfamily present in bacterial polymorphic toxin systems. The domain has characteristic histidine, tyrosine and aspartate residues that comprise the active site. In bacterial polymorphic toxin systems, the toxin is exported by the type 2, type 6, or type 7 secretion system [1]. ART-HYD1 domain toxin from Photorhabdus has been shown to have antibacterial activity and arrest translation by ADP-ribosylating specific position of 23S rRNA [2].

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

2: Photorhabdus antibacterial Rhs polymorphic toxin inhibits translation through ADP-ribosylation of 23S ribosomal RNA. Jurenas D, Payelleville A, Roghanian M, Turnbull KJ, Givaudan A, Brillard J, Hauryliuk V, Cascales E; Nucleic Acids Res. 2021 Jul 13. pii: 6320; [Epub ahead of print] PMID:34255843