Part of the high-affinity ABC transporter complex ZnuABC involved in zinc import (Probable). Responsible for energy coupling to the transport system (By similarity). ZnuABC-mediated zinc transport is required for comF expression and competence development. ATP(in) + H2O(in) + Zn(2+)(out) = ADP(in) + H(+)(in) + phosphate(in) + Zn(2+)(in) The complex is composed of two ATP-binding proteins (ZnuC), two transmembrane proteins (ZnuB) and a solute-binding protein (ZnuA). Repressed by zinc via the metallo-regulatory protein Zur. Disruption results in low transformability. Belongs to the ABC transporter superfamily.