Ubiquitin-associated domain (UBA) is a small common sequence (~45 residues) found in various proteins associated with the ubiquitin/proteasome pathway, DNA excision-repair, and cell signalling (in certain protein kinases). The structure of the UBA domain consists of a compact three-helix bundle. It has been suggested that UBA domains are involved in conferring target specificity to multiple enzymes of the ubiquitination system.

The mechanism of ubiquitin binding to UBA is predicted to occur via the hydrophobic surface patch of UBA domains, which interacts with the hydrophobic surface on the five-stranded beta-sheet of ubiquitin.

INTERPRO:IPR015940, PFAM:PF00627,DOI:10.1016/S0022-2836(02)00302-9,DOI:10.1016/S0968-0004(96)30015-7,DOI:10.1038/4220