| Domain | Name | Category | Type |
| IPR000011 | Ubiquitin/SUMO-activating enzyme E1 | Family | Family |
| IPR000594 | THIF-type NAD/FAD binding fold | Domain | Domain |
| IPR018074 | Ubiquitin-activating enzyme E1, conserved site | Site | Conserved site |
| IPR018075 | Ubiquitin-activating enzyme E1 | Family | Family |
| IPR018965 | Ubiquitin-activating enzyme E1, C-terminal | Domain | Domain |
| IPR019572 | Ubiquitin-activating enzyme, SCCH domain | Domain | Domain |
| IPR032418 | Ubiquitin-activating enzyme E1, FCCH domain | Domain | Domain |
| IPR032420 | Ubiquitin-activating enzyme E1, four-helix bundle | Domain | Domain |
| IPR033127 | Ubiquitin-activating enzyme E1, Cys active site | Site | Active site |
| IPR035985 | Ubiquitin-activating enzyme | Family | Homologous superfamily |
| IPR038252 | Ubiquitin-activating enzyme E1, C-terminal domain superfamily | Family | Homologous superfamily |
| IPR042063 | Ubiquitin-activating enzyme E1, SCCH domain | Family | Homologous superfamily |
| IPR042302 | Ubiquitin-activating enzyme E1, FCCH domain superfamily | Family | Homologous superfamily |
| IPR042449 | Ubiquitin-activating enzyme E1, inactive adenylation domain, subdomain 1 | Family | Homologous superfamily |