label: ISG15 conjugating enzyme activity
label_lc: isg15 conjugating enzyme activity
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."