1. Laboratory of Nanoscale Biology, Institute of Bioengineering, School of Engineering, EPFL, 1015 Lausanne, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
2. Laboratory for Crystallography, Institute of the Physics of Biological Systems, School of Basic Sciences, EPFL, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland