The zntA gene of Escherichia coli encodes a Zn(II)-translocating P-type ATPase

The first Zn(II)-translocating P-type ATPase has been identified as the product of o732, a potential gene identified in the sequencing of the Escherichia coli genome, This gene, termed zntA, was disrupted by insertion of a kanamycin gene through homologous recombination. The mutant strain exhibited hypersensitivity to zinc and cadmium salts but not salts of other metals, suggesting a role in zinc homeostasis in E. coli. Everted membrane vesicles from a wild-type strain accumulated Zn-65(II) and Cd-109(II) by using ATP as an energy source, Transport was sensitive to vanadate, an inhibitor of P-type ATPases. Membrane vesicles from the zntA::kan strain did not accumulate those metal ions, Both the sensitive phenotype and transport defect of the mutant were complemented by expression of zntA on a plasmid.