Investigation of the peculiar nickel-binding site of the metalloprotein CooT by hyperpolarized solid-state NMR
Published : 11 October 2019
With its tuneable chemical reactivity, cysteine plays crucial roles as Ni ligands in active sites of redox Ni enzymes. Instead, histidines are preferred to coordinate Ni(II) ions in non-redox proteins. Interestingly, cysteine exhibits extreme patterns of conservation, being either highly conserved or completely degenerated, with a strong tendency to form buried cysteine clusters. The case of the nickel chaperone CooT is intriguing as the binding site is formed by the dimerization of the protein that only contains a single strictly conserved and solvent-exposed cysteine. The solvent exposure of the Ni-binding site as well as its position at the dimer interface are two drawbacks for structural studies. The goal of this project is to use Dynamic Nuclear Polarization (DNP)-enhanced solid-state NMR to investigate precisely this original nickel-binding site, by enhancing significantly the sensitivity and selectivity.