Novel insights into nickel import in Staphylococcus aureus: the positive role of free histidine and structural characterization of a new thiazolidine-type nickel chelator.
Lebrette, H., Borezee-Durant, E., Martin, L., Richaud, P., Boeri Erba, E., Cavazza, C.(2015) Metallomics 7: 613-621
- PubMed: 25611161 
- DOI: https://doi.org/10.1039/c4mt00295d
- Primary Citation of Related Structures:  
4OFJ, 4XKN, 4XKP, 4XKQ, 4XKR - PubMed Abstract: 
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.
Organizational Affiliation: 
Univ. Grenoble Alpes, Institut de Biologie Structurale (IBS), F-38044 Grenoble, France.