Immunogen sequence: LNEPNTFSPA NVDASVMYRK WKESKGKDRE YTDIIRKQVL GTKVDAERDG VKVPTTLAEY CVKTKAPAPD EGSDLFYDDY YEDGEVEEEA DSCFGDDEDD SGT. Accepts ubiquitin from the E1 complex and catalyzes its covalent attachment to other proteins. In vitro catalyzes 'Lys-