3000 FDA-approved drugs were screened against NEDD8-activating enzyme in silico.
Piperacillin 1 inhibited NAE activity in cell-free and cell-based systems.
Piperacillin 1 was selective for NAE over SAE and ubiquitin E2 in human cells.
Molecular modeling revealed piperacillin 1 bound to the ATP-binding region of NAE.