ATPase component of the type III secretion system (T3SS), also called injectisome, which is used to inject bacterial effector proteins into eukaryotic host cells (By similarity). Acts as a molecular motor to provide the energy that is required for the export of proteins (By similarity). Required for type III secretion apparatus (T3SA) formation, proper protein secretion, host cell invasion and virulence (By similarity). May play a critical role in T3SS substrate recognition, disassembly of the effector/chaperone complex and unfolding of the effector in an ATP-dependent manner prior to secretion (By similarity). ATP + H2O + cellular proteinSide 1 = ADP + phosphate + cellular proteinSide 2. The core secretion machinery of the T3SS is composed of approximately 20 different proteins, including cytoplasmic components, a base, an export apparatus and a needle (PubMed:30107569). This subunit is part of the cytosolic complex (By similarity). Forms homohexamers (By similarity). Belongs to the ATPase alpha/beta chains family. T3SS ATPase subfamily.