canonical GAT domain found in target of myb protein 1 (Tom1) protein family
Tom1 and its related proteins, Tom1L1 and Tom1L2, form a protein family sharing an N-terminal VHS (Vps27p/Hrs/STAM)-domain followed by a GAT (GGA and TOM1) domain, both of which are also conserved in Golgi-localized gamma ear-containing Arf-binding proteins (GGAs). In contrast to GGAs, the Tom1 family proteins bind to ubiquitin, ubiquitinated proteins, and Toll-interacting protein (Tollip) through its GAT domain, but do not associate with Arf GTPases through its GAT domain nor with acidic cluster-dileucine sequences through its VHS domain. In addition, the Tom1 family proteins recruit clathrin onto endosomes through their C-terminal region. In their C-terminal clathrin-binding regions, Tom1 and Tom1L2 are similar to each other, but distinguishable from Tom1L1. The yeast S. cerevisiae does not contain homologous proteins of the Tom1 family. The canonical GAT domain is a monomeric three-helix bundle that binds ubiquitin.