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. Forms homooligomers; most probably hexamers (By similarity). Interacts with OutL/GspL (By similarity). Membrane association is not an intrinsic property but requires the OutL/GspL gene product. Belongs to the GSP E family.