Deubiquitinase that recognizes and hydrolyzes the peptide bond at the C-terminal Gly of ubiquitin. May play a role in the regulation of NF-kappa-B signaling pathway by deubiquitinating TRAF2. ; (Microbial infection) Plays a positive role in foot-and-mouth disease and classical swine fever viral infection. Mechanistically, associates with internal ribosomal entry site (IRES) element within the 5′-untranslated region of viral genomes to promote translation of the virus-encoded polyprotein.