UBA2 domain of putative DNA repair proteins RAD23 found in plant
The radiation sensitive 23 (RAD23) subfamily consists of four isoforms of putative DNA repair proteins from Arabidopsis thaliana and similar proteins from other plants. The nuclear-enriched RAD23 proteins function in the cell cycle, morphology, and fertility of plants through their delivery of ubiquitin (Ub)/26S proteasome system (UPS) substrates to the 26S proteasome. RAD23 proteins contain an N-terminal ubiquitin-like (UBL) domain that associates with the 26S proteasome Ub receptor RPN10, and two C-terminal ubiquitin-associated (UBA) domains that bind Ub conjugates. This model corresponds to the UBA2 domain.