Part of the ABC transporter complex NikABCDE involved in nickel import. Responsible for energy coupling to the transport system. ATP + H2O + Ni(2+)(out) = ADP + H(+) + Ni(2+)(in) + phosphate The complex is composed of two ATP-binding proteins (NikD and NikE), two transmembrane proteins (NikB and NikC) and a solute-binding protein (NikA). Induced by low oxygen tension and metal ion deficiency. Repressed by NiCl(2) excess. Belongs to the ABC transporter superfamily. Nickel importer (TC 3.A.1.5.3) family.