label: Pup conjugating enzyme activity
label_lc: pup conjugating enzyme activity
description: "Isoenergetic transfer of Pup from one protein to another via the reaction X-Pup + Y = Y-Pup + X, where both the X-Pup and Y-Pup linkages are thioester bonds between the C-terminal amino acid of Pup and a sulfhydryl side group of a cysteine residue."