Catalysis of the transfer of NEDD8 to a substrate protein via the reaction X-NEDD8 + S = X + S-NEDD8, where X is either an E2 or E3 enzyme, the X-NEDD8 linkage is a thioester bond, and the S-NEDD8 linkage is an isopeptide bond between the C-terminal amino acid of NEDD8 and the epsilon-amino group of lysine residues in the substrate.
E3