Description
SAE1 belongs to the ubiquitin-activating E1 family. It is a heterodimer that acts as a E1 ligase for SUMO1, SUMO2, SUMO3, and probably SUMO4. It functions as a UBLI E1 ligase mediating the ATP-dependent activation of UBL1. SAE1 binds with UBLE1A and UBLE1B to form a heterodimer which can bind UBL1. SAE1 also regulates ATP-dependent activation of SUMO proteins and formation of a thioester with a conserved cysteine residue on SAE2. SAE1 and UBA2 form a heterodimer that functions as a SUMO-activating enzyme for the sumoylation of proteins