ATPase component of the type II secretion system required for the energy-dependent secretion of extracellular factors such as proteases and toxins from the periplasm. Acts as a molecular motor to provide the energy that is required for assembly of the pseudopilus and the extrusion of substrates generated in the cytoplasm. ATP + H2O + cellular proteinSide 1 = ADP + phosphate + cellular proteinSide 2. Removal of zinc reduces the enzymatic activity by about 2-fold. Forms homooligomers; most probably hexamers (PubMed:15601709, PubMed:23954505) (Probable). Interacts with EpsL/GspL (PubMed:15843017). Membrane association is not an intrinsic property but requires the EpsL/GspL gene product. Deletion mutants show complete loss of protease secretion. Belongs to the GSP E family.