| Domain | Name | Category | Type |
| IPR003323 | OTU domain | Domain | Domain |
| IPR016615 | Ubiquitin thioesterase Otubain | Family | Family |
| IPR019400 | Peptidase C65, otubain | Family | Family |
| IPR030298 | Ubiquitin thioesterase OTUB1 | Family | Family |
| IPR038765 | Papain-like cysteine peptidase superfamily | Family | Homologous superfamily |
| IPR042467 | Peptidase C65, otubain, subdomain 2 | Family | Homologous superfamily |
| IPR042468 | Peptidase C65, otubain, subdomain 1 | Family | Homologous superfamily |