Antitoxin component of a hybrid type II/IV toxin-antitoxin (TA) system. De-ADP-ribosylates DNA modified on thymidine by its cognate toxin DarT, which neutralizes the activity of cognate toxin DarT. Upon expression in E.coli neutralizes the effect of cognate toxin DarT (PubMed:27939941). Upon expression in M.tuberculosis neutralizes the toxic effects of endogenous DarT (PubMed:32634279). an N-(ADP-alpha-D-ribosyl)-thymidine in DNA + H2O = a thymidine in DNA + ADP-D-ribose Probably forms a complex with cognate toxin DarT; this complex might decrease ADP-ribosylation activity of DarT. The macro domain alone is able to de-ADP-ribosylate substrate in vitro and is almost as effective at neutralizing DarT in growth experiments as full-length protein. Belongs to the DarG ADP-ribosyl glycohydrolase family.