UbcH6/UBE2E1: ProductsUbiquitin-conjugating Enzyme H6 (UbcH6), also known as Ubiquitin-conjugating Enzyme E2E 1 (UBE2E1), is a ubiquitously expressed protein with a predicted molecular weight of 21 kDa. Human UbcH6/UBE2E1 shares 99% and 100% amino acid sequence identity with mouse and rat UBE2E1, respectively. UbcH6/UBE2E1 mediates the selective degradation of short-lived and abnormal proteins. UbcH6/UBE2E1 catalytic activity is modulated following the addition of the Ubiquitin-like protein ISG15 to Lys136. In the nucleus, the N-terminal fragment of UbcH6/UBE2E1 interacts with the Ubiquitin ligase (E3) TRIM21 to mediate substrate ubiquitination. UbcH6/UBE2E1 also interacts with the viral E3, ICP0, during HSV-1 infection. In addition, UbcH6/UBE2E1-dependent protein ubiquitination is implicated in polyglutamine tract disorders such as ataxia.