Disease relevance of zntA

• The zntA gene of Escherichia coli encodes a Zn(II)-translocating P-type ATPase [1].
• A chromosomally encoded znt operon of Staphylococcus aureus consists of two consecutive putative genes designated zntR and zntA [2].

High impact information on zntA

• Both the sensitive phenotype and transport defect of the mutant were complemented by expression of zntA on a plasmid [1].
• This gene, termed zntA, was disrupted by insertion of a kanamycin gene through homologous recombination [1].
• Heterologous expression of H. pylori cadA in an Escherichia coli zntA mutant resulted in an elevated resistance to Cd(II) and Zn(II) [3].
• The zntA gene encodes a transmembrane protein that facilitates extrusion of Zn2+ and Co2+, whereas the zntR gene encodes a putative regulatory protein that controls the expression of the znt operon [2].
• We have identified the promoter/operator region of the zntA gene of Escherichia coli and shown that Zn(II) is the primary inducer of expression of this Zn(II)/Cd(II) export gene [4].

Chemical compound and disease context of zntA

• Expression of zntA from R. metallidurans in Escherichia coli predominantly mediated resistance to zinc, and expression of cadA predominantly mediated resistance to cadmium [5].

Biological context of zntA

• The mutated gene, located between 75.5 and 76.2 min on the chromosome, is named zntA (for Zn(II) transport or tolerance) [6].
• The Cd(II)- and Pb(II)-dependent transcriptional up-regulation of zntA is also mediated by ZntR [7].
• In the plasmid-free R. metallidurans strain AE104, single gene deletions of cadA or zntA had only a moderate effect on cadmium and zinc resistance, but zinc resistance decreased 6-fold and cadmium resistance decreased 350-fold in double deletion strains [5].
• A genetically modified Escherichia coli strain, containing the lacZ reporter gene fused to the heavy metal-responsive gene promoter zntA, was used to fabricate a mercury biosensor [8].

Associations of zntA with chemical compounds

• Exposure of the zntA mutant to cobalt(II) and cadmium(II) also resulted in elevated levels of intracellular and cell surface-bound metal ions [6].
• In contrast, expression of zntA was induced by both zinc and cadmium, and the induction pattern did not change in the presence or absence of CadA [5].

Other interactions of zntA

• In the absence of the zntA gene, expression of cadA occurred at lower cadmium concentrations and zinc now served as an inducer [5].
• AtHMA4 was able to restore growth at high [Zn] in the zntA mutant but not at high [Cu] in the copA mutant, suggesting a role in zinc transport [9].

References