CzcC protein appears to modify the specificity of the system, perhaps by acting on the CzcB protein. When the CzcC protein is added to CzcA and CzcB, the efflux system gains specificity for cadmium and cobalt. By zinc, cadmium and cobalt (zinc being the best and cobalt being the worst inducer). In the presence of 2 mM Cd(2+) or 4-10 mM Zn(2+) up to 99% of the metal is removed from the culture supernatant and is sequestered via bioprecipitation. Additionally Cu(2+), Co(2+), Ni(2+), Pb(2+), Y(3+) and Ge(4+) can also be removed from culture supernatants, although it is not clear which efflux system is responsible for all these substrates (PubMed:7766206). Belongs to the outer membrane factor (OMF) (TC 1.B.17) family.