Ubiquitin-like protein peptidases catalyse the hydrolysis of the peptide or isopeptide bond between ubiquitin or a ubiquitin-like protein (e.g. ATG8, NEDD8, SUMO, UFM1) and the larger protein to which it has been conjugated. They also cleave the bonds within chains of ubiquitin(-like) proteins. As such, they reverse the modification of proteins by a single ubiquitin(-like) protein, and remodel polyubiquitin(-like) chains on target proteins. The majority of ubiquitin-like protein proteases are cysteine-type peptidases, though some are metallopeptidases (this group). (Adapted from PMID:19489724.)