Parkin–phosphoubiquitin complex reveals cryptic ubiquitin-binding site required for RBR ligase activity

The human RBR E3 ligase Parkin is captured in complex with phosphoubiquitin, revealing a cryptic ubiquitin-binding site and indicating a mechanism of cooperation between RBR modules for activation. RING-between-RING (RBR) E3 ligases are a class of ubiquitin ligases distinct from RING or HECT E3 ligases. An important RBR ligase is Parkin, mutations in which lead to early-onset hereditary Parkinsonism. Parkin and other RBR ligases share a...