NEDD8-activating enzyme E1 catalytic subunit (UBA3)

Catalytic subunit of the dimeric UBA3-NAE1 E1 enzyme. E1 activates NEDD8 by first adenylating its C-terminal glycine residue with ATP, then linking this residue to the side chain of the catalytic cysteine, yielding a NEDD8-UBA3 thioester and free AMP.

E1 eventually transfers NEDD8 to the catalytic cysteine of UBE2M. Down-regulates steroid receptor activity.