Posttranslational modification of proteins by the addition of the small protein SUMO (see SUMO1, MIM 601912), or sumoylation, regulates protein structure and intracellular localization. SAE1 (MIM 613294) and UBA2 form a heterodimer that functions as a SUMO-activating enzyme for the sumoylation of proteins (Okuma et al., 1999 [PubMed 9920803]).[supplied by OMIM, Mar 2010],function:The dimeric enzyme acts as a E1 ligase for SUMO1, SUMO2, SUMO3, and probably SUMO4. It mediates ATP-dependent activation of SUMO proteins and formation of a thioester with a conserved cysteine residue on SAE2.,pathway:Protein modification, protein sumoylation.,similarity:Belongs to the ubiquitin-activating E1 family.,subunit:Heterodimer of SAE1 and SAE2. The complex binds SUMO proteins via SAE2.,
