ATPase component of the type IV secretion system Cag (Cag-T4SS). Acts as a molecular motor to provide the energy that is required for the export of proteins. Required for CagA translocation and induction of IL-8 in host gastric epithelial cells. Plays a key role in Cag-T4SS pilus biogenesis, especially in the localization and stabilization of the pilus-associated components CagI, CagL and the surface protein CagH. Is also critical for assembly of the entire cytoplasmic portion of the Cag inner membrane complex (IMC). ATP + H2O + cellular proteinSide 1 = ADP + phosphate + cellular proteinSide 2. Component of the Cag type IV secretion system, which is composed of a wheel-shaped outer membrane complex (OMC) and an inner membrane complex (IMC) (By similarity). Interacts with CagV and CagBeta (By similarity). Belongs to the TrbE/VirB4 family.