1. Laboratoire Physico-Chimie, Institut Curie, CNRS UMR168,
Paris-Science Lettres, Université Pierre et Marie Curie-Paris 6, 75005 Paris, France
2. Department of Biology, University of Osnabrück, 49076 Osnabrück, Germany
3. Sorbonne Universités, UPMC Univ Paris 06, UMR 8234, PHENIX, F-75005 Paris, France