Structural basis for specific cleavage of Lys 63-linked polyubiquitin chains

Deubiquitinating enzymes catalyse the removal of ubiquitin chains conjugated to substrates. In this study, Sato et al. determine the crystal structure of a deubiquitnating enzyme called AMSH alone and in complex with a Lys-63-linked di-ubiquitin chain. The complex reveals the structural basis for specific cleavage of Lys-63 ubiquitin chains and is the first report of a deubiquitnating enzyme in complex with an isopeptide-linked ubiquitin chain.