Novel insights into nickel import in Staphylococcus aureus: the positive role of free histidine and structural characterization of a new thiazolidine-type nickel chelator

Metallomics. 2015 Apr;7(4):613-21. doi: 10.1039/c4mt00295d.


Staphylococcus aureus possesses two canonical ABC-importers dedicated to nickel acquisition: the NikABCDE and the CntABCDF systems, active under different growth conditions. This study reports on the extracytoplasmic nickel-binding components SaNikA and SaCntA. We showed by protein crystallography that SaNikA is able to bind either a Ni-(l-His)2 complex or a Ni-(l-His) (2-methyl-thiazolidine dicarboxylate) complex, depending on their availability in culture supernatants. Native mass spectrometry experiments on SaCntA revealed that it binds the Ni(ii) ion via a different histidine-dependent chelator but it cannot bind Ni-(l-His)2. In vitro experiments are consistent with in vivo nickel content measurements that showed that l-histidine has a high positive impact on nickel import via the Cnt system. These results suggest that although both systems may require free histidine, they use different strategies to import nickel.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP-Binding Cassette Transporters / chemistry*
  • Bacterial Proteins / chemistry
  • Chelating Agents / chemistry
  • Crystallography
  • Cytoplasm / metabolism
  • Escherichia coli / metabolism
  • Histidine / chemistry*
  • Mass Spectrometry
  • Nickel / chemistry*
  • Protein Conformation
  • Staphylococcus aureus / metabolism*
  • Thiazolidines / chemistry*


  • ATP-Binding Cassette Transporters
  • Bacterial Proteins
  • Chelating Agents
  • Thiazolidines
  • Histidine
  • Nickel