1 CNR-Institute of Biophysics, Via alla Cascata, 56, 38123, Trento, Italy.
2 Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK. gilbert@strubi.ox.ac.uk.
3 Centre for Protein Engineering, Department of Life Sciences, Institut de Chimie B6, Allée de la Chimie, 3, University of Liège, 4000, Liège (Sart-Tilman), Belgium.
4 Institut Pasteur, Biophysics of Macromolecules and their Interactions, 25 rue du Docteur Roux, 75015, Paris, France.