Part of the tripartite efflux system PvdRT-OpmQ required for the secretion into the extracellular milieu of the siderophore pyoverdine (PVD), which is involved in iron acquisition. This subunit binds PVD and drives its secretion by hydrolyzing ATP. The system is responsible for export of newly synthesized PVD after the final steps of biosynthesis have taken place in the periplasm. It is also responsible for recycling of PVD after internalization of ferri-PVD into the periplasm by the outer-membrane receptor FpvA and release of iron from PVD, thus making PVD available for new cycles of iron uptake 