Deubiquitinating enzyme. Has almost no deubiquitinating activity by itself and requires the interaction with wdr48 to have a high activity. Thiol-dependent hydrolysis of ester, thioester, amide, peptide and isopeptide bonds formed by the C-terminal Gly of ubiquitin (a 76-residue protein attached to proteins as an intracellular targeting signal). Interacts with WDR48. Belongs to the peptidase C19 family. USP12/USP46 subfamily. Conflict that suppressed the initiatory methionine.