A family of ADP-Ribosyltransferases found in polyvalent proteins of phages and conjugative elements. These are in turn related to the Tox-ART-HYD2 group of ADP-Ribosyltransferases that are seen in polymorphic toxin systems and in toxin-antitoxin systems. These are predicted to modify host proteins [1].

1: Polyvalent Proteins, a Pervasive Theme in the Intergenomic Biological Conflicts of Bacteriophages and Conjugative Elements. Iyer LM, Burroughs AM, Anand S, de Souza RF, Aravind L; J Bacteriol. 2017; [Epub ahead of print] PMID:28559295