Part of the ABC transporter complex ThiBPQ involved in thiamine import. Responsible for energy coupling to the transport system. ATP + H2O + thiamine(out) = ADP + H(+) + phosphate + thiamine(in) The complex is composed of two ATP-binding proteins (ThiQ), two transmembrane proteins (ThiP) and a solute-binding protein (ThiB). Belongs to the ABC transporter superfamily. Thiamine importer (TC 3.A.1.19.1) family.