The covalent attachment of ubiquitin to proteins is a common regulatory mechanism in a number of cellular processes. Ubiquitination of a substrate requires the activity of a cascade of three enzymes, ...

Sister chromatid separation and exit from mitosis are initiated by a 1.5-MDa ubiquitin ligase (E3) composed of at least 13 subunits and known as the anaphase-promoting complex/cyclosome (APC/C) 1. The ...