FIG. 3.

Domain structures of the human Pl-MART family. A new classification and a schematic comparison of protein structures of the 11 members of the Pl-MART family, based on the literature and database searches, are shown. The most significant domains detected have been indicated. The WWE domain is named after three of its conserved residues (W/W/E) and is predicted to mediate specific protein-protein interactions in ubiquitin- and ADP-ribose conjugation systems (24). Although the exact roles of the conserved macroH2A/A1pp domains remain unknown, they have been proposed to have ADP-ribose 1"-phosphate (Appr-1"p)-processing activity and may regulate mono-ADP-ribosylation (219). ZF, C3H-type zinc finger domain; RRM, RNA recognition motif (252); UIM, ubiquitin interaction motif (22); MVP-ID, M-vault particle interaction domain; TPH, Ti-PARP homologous domain; GRD, glycine-rich domain.