Ubiquitin­conjugating Enzyme H7 (UbcH7), also known as Ubiquitin­conjugating Enzyme E2L 3 (UBE2L3), is a member of the Ubiquitin­conjugating (E2) enzyme family. It has a predicted molecular weight of approximately 18 kDa. The human UbcH7 protein shares 100% amino acid (aa) sequence identity with the mouse and rat orthologs. UbcH7 has an E2 catalytic core domain that contains an active site cysteine residue and comprises 152 of its 154 aa residues. UbcH7 is catalytically active with HECT and RBR domain­containing families of Ubiquitin ligases (E3s). UbcH7 localizes to both the nucleus and cytoplasm in human cells. In mice, its ortholog is expressed in many tissues including brain, muscle, heart, lung, lymph node, spleen, thymus, and testis. UbcH7 depletion results in an extended S phase and a reduced rate of proliferation, suggesting that it may play a role in the cell cycle. In humans, single nucleotide polymorphisms in UbcH7 are associated with systemic lupus erythematosus and Crohn's disease, suggesting that UbcH7 is important for proper immune system function.