SUMO activating enzyme E1 (human), (recombinant)

SUMO conjugation to target proteins is mediated by a different, but analogous, pathway to ubiquitinylation. SUMO activating enzyme is a heterodimeric complex consisting of Aos1 and Uba2. Both subunits are well conserved from yeast to humans, with Aos2/SAE I being similar to the N-terminal half of the E1 enzyme for ubiquitin while Uba2/SAE II has similarity to the C-terminal half, and contains the active site cysteine residue required for formation of thioester bonds. However, Uba2 alone is not sufficient to catalyze SUMOylation. SUMO1 activating enzyme supports in vitro SUMOylation.