Structure and Metal binding Characterization of the C-terminal Mellochaperone Domain of Membrane Fusion Protein SilB from Cupriavidus metallidurans CH34

Beate Bersch, Kheiro-mouna Derfoufi, Fabien de Angelis, Vanessa Auquier, Elisabeth Ngonlong Ekende, Max Mergeay, Jean-Marie Ruysschaert, Guy Vandenbussche, Pieter Monsieurs

    Research outputpeer-review


    In Cupriavidus metallidurans CH34, a model organism for heavy metal resistance studies, the sil determinant is potentially involved in the efflux of of silver and copper ions. Proteins SilA, SilB, SilC form a resistance/nodulation/cell division (RND)-based transport system in which SilB is the periplasmic adaptor protein belonging to the membrane fusion protein family. In addition sto the four domains typical of known MFPs, SilB has a fifth additional C-terminal domain , SilB440-521. Structure and backbone of SilB440-521 have been investigated using NMR, and the residues of the metal site have been from 15N- and 13C-edited HSQC spectra.The solution structure and additional metal binding experiments that this C-terminal domain folds independantly of the rest of the protein and has a conformation and a Ag+ /Cu+ binding specificity similar to those determined for CusF from Escherichia coli. The samll protein CusF plays a role in metal trafficking in the periplasm. This suggests a potential metallochaperone role for SilB440-521 that is discussed in the context of simultaneous expression of different determinants involved in copper resistance in C.metallidurans CH34
    Original languageEnglish
    Pages (from-to)2194-2204
    Issue number12
    StatePublished - 7 Feb 2011

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