Purity > 90% as determined by SDS-PAGE. MW: 39.9kDa. Partial: 542-870aa. N-terminal 6xHis-tagged. Mus musculus (Mouse). E3 ubiquitin-protein ligase which accepts ubiquitin from an E2 ubiquitin-conjugating enzyme in the form of a thioester and transfers it to its substrates. Several substrates have been identified including the RAD23A and RAD23B, MCM7 (which is involved in DNA replication), annexin A1, the PML tumor suppressor, and the cell cycle regulator CDKN1B. Additionally, may function as a cellular quality control ubiquitin ligase by helping the degradation of the Cytoplasmic domain misfolded proteins. Finally, UBE3A also promotes its own degradation in vivo (By similarity). Plays an important role in the regulation of the circadian clock: involved in the ubiquitination of the core clock component ARNTL/BMAL1, leading to its proteasomal degradation (PubMed:24728990).