Category: Database: Enzyme
RING Finger Ubiquitin Ligase
RING finger ubiquitin ligases are the largest class of E3 enzymes in the ubiquitin–proteasome system, defined by a zinc‑binding cross‑brace RING domain that positions E2~Ub for direct ubiquitin transfer. They regulate essential cellular processes including cell cycle progression, DNA repair, immunity, and neuronal function. Dysregulation of RING and RBR ligases such as MDM2 and Parkin contributes to cancer and neurodegeneration, while modern PROTAC therapeutics harness CRL4^CRBN and CRL2^VHL complexes to redirect ubiquitination toward disease‑associated proteins.
Ubiquitin Ligase
E3 ubiquitin ligases are key regulators of protein ubiquitination and cellular protein homeostasis. They provide substrate specificity within the ubiquitin system and regulate protein degradation, cell-cycle progression, DNA repair, immune signalling, apoptosis, and other essential cellular processes.