ATPase component of the type II secretion system required for the energy-dependent secretion of extracellular factors from the periplasm (By similarity). Acts as a molecular motor to provide the energy that is required for the export of proteins (By similarity). The Hxc system is involved in the secretion of low-molecular-weight alkaline phosphatase L-AP (LapA) (PubMed:11985723). Is probably also involved in the secretion of the phosphate-binding protein PstS (PubMed:18282104). ATP + H2O + cellular proteinSide 1 = ADP + phosphate + cellular proteinSide 2. Induced by phosphate limitation. Mutant cannot secrete the low-molecular-weight alkaline phosphatase LapA (PubMed:11985723). Deletion mutant shows decreased ability to express outer surface PstS, but not intracellular PstS (PubMed:18282104). Belongs to the GSP E family.