| Namespace | molecular_function | Obsolete | false |
| description | Isoenergetic transfer of ISG15 from one protein to another via the reaction X-ISG15 + Y = Y-ISG15 + X, where both the X-ISG15 and Y-ISG15 linkages are thioester bonds between the C-terminal amino acid of ISG15 and a sulfhydryl side group of a cysteine residue. |
