Immunity component of a contact-dependent interbacterial competition system (also called effector-immunity systems). Acts as an arginine mono-ADP-ribosylhydrolase, mediating the removal of mono-ADP-ribose attached to arginine residues on proteins. De-ADP-ribosylates FtsZ, is able to act on other proteins as well. Neutralizes the toxic activity of cognate toxin Tre1-Sp. Expression of this protein alone in E.coli partially protects the cells against competition by wild-type S.proteamaculans. Neutralizes Tre1-Sp both by occluding its active site via its N-terminal extension and by hydrolyzing the ADP-ribosyl moiety from FtsZ; the 2 activities are dissociable by mutagenesis. H2O + N(omega)-(ADP-D-ribosyl)-L-arginyl-[protein] = ADP-D-ribose + L-arginyl-[protein] Binds 1 Mg(2+) ion per subunit. Forms a stable complex with cognate effector protein Tre1-Sp. The N-terminal extension forms a projection that reaches into the active site of cognate toxin Tre1-Sp where it occludes the active site. A double tre1-tri1 deletion is outcompeted by wild-type cells, but not by wild-type cells missing a type 6 secretion system (T6SS). Belongs to the ADP-ribosylglycohydrolase family.