a ubiquitin-activating enzyme (E1, two types), a ubiquitin-conjugating enzyme (E2, 40 types), and a ubiquitin ligase (E3, over 600 types). This reaction is repeated to form ubiquitin chains.

Covalent modification of the oncogene product Mdm2 by the ubiquitin-related protein SUMO1 protects it from ubiquitination and enhances its E3 ligase activity towards p53 in vitro. Disappearance of ...

During ubiquitination, a small protein known as ubiquitin is attached to other proteins by a class of enzymes known as E3 ...