I have a small bacterial protein (7kDa) potentially involved in stress response which has the capacity to interact with different kind of metals such as Ni2+, Cu2+, Fe2+, Zn2+, Co2+ and Cd2+. No interaction was detected with other metal ions. I have demonstrated the interaction by X-ray crystallography, Circular Dichroïsm, Isothermal Titration Calorimetry and Thermal Shift Assay but I have no idea of its physiological role.