Ubiquitin carboxyl-terminal hydrolase 20 is an enzyme that in humans is encoded by the USP20 gene.
Ubiquitin-specific protease 20 (USP20), also known as ubiquitin-binding protein 20 and VHL protein-interacting deubiquitinating enzyme 2 (VDU2), is a cysteine protease deubiquitinating enzyme (DUB). The catalytic site of USP20, like other DUBs, contains conserved cysteine and histidine residues that catalyse the proteolysis of an isopeptide bond between a lysine residue of a target protein and a glycine residue of a ubiquitin molecule. USP20 is known to deubiquitinate a number of proteins including thyronine deiodinase type 2 (D2), Hypoxia-inducible factor 1α (HIF1α), and β2 adrenergic receptor (β2AR).