Macrodomains are found in a variety of proteins with diverse cellular functions, as a stand-alone domain or in combination with other domains like in histone macroH2A and some PARPs (poly ADP-ribose polymerases). Macrodomains can recognize ADP-ribose (ADPr) in both its free and protein-linked forms, in related ligands, such as O-acyl-ADP-ribose (OAADPr), and even in ligands unrelated to ADPr. Members of this family show similarity to the yeast protein Poa1p, reported to be a phosphatase specific for Appr-1"-p, a tRNA splicing metabolite. Poa1p may play a role in tRNA splicing regulation.
Jiyao W et al.(2023). "The conserved domain database in 2023.",