1. FOM Institute for Atomic and Molecular Physics (AMOLF), Science Park 104, 1098 XG Amsterdam, The Netherlands
2. The Netherlands Proteomics Centre, Padualaan 8, 3584 CH Utrecht, The Netherlands
3. Cluster of Excellence Macromolecular Complexes, Institute of Pharmaceutical Chemistry, Goethe-University Frankfurt, Max-von-Laue-Strasse 9, 60438 Frankfurt, Germany
4. Institute of Medical Physics and Biophysics, University of Muenster, Robert-Koch-Strasse 31, 48149 Muenster, Germany