– Ubiquitin-Conjugating Enzyme E2 (UBE2A) is a member of the E2 Ubiquitin-Conjugating Enzyme family. The modification of proteins with ubiquitin is an important cellular mechanism for targeting abnormal or short-lived proteins for degradation. Ubiquitination involves at least three classes of enzymes: ubiquitin-activating enzymes, or E1s, ubiquitin-conjugating enzymes, or E2s, and ubiquitin-protein ligases, or E3s. UBE2A catalyzes the covalent attachment of ubiquitin to other proteins. UBE2A is required for postreplication repair of UV-damaged DNA. UBE2A Interacts with RAD18 and WAC.