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, ubiquitin-conjugating enzymes, and ubiquitin-protein ligases. This gene encodes a member of the E2 ubiquitin-conjugating enzyme family. This enzyme is required for post-replicative DNA damage repair, and may play a role in transcriptional regulation. Mutations in this gene are associated with mental retardation. Alternative splicing results in multiple transcript variants.UBE2A (Ubiquitin Conjugating Enzyme E2 A) is a Protein Coding gene. Diseases associated with UBE2A include Mental Retardation, X-Linked Syndromic, Nascimento-Type. Among its related pathways are Innate Immune System and Class I MHC mediated antigen processing and presentation. An important paralog of this gene is UBE2B. UBE2B (Ubiquitin Conjugating Enzyme E2 B) is a Protein Coding gene. Diseases associated with UBE2B include Aggressive Systemic Mastocytosis. Among its related pathways are Innate Immune System and Class I MHC mediated antigen processing and presentation. GO annotations related to this gene include ligase activity and ubiquitin protein ligase binding. An important paralog of this gene is UBE2A.