1. Ruhr University Bochum, Department of Biophysics , Universitätsstraße 150, D-44780 Bochum , Germany
2. Forschungszentrum Jülich GmbH, Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons / ER-C-3: Structural Biology , D-52425 Jülich , Germany
3. Forschungszentrum Jülich GmbH, Institute for Biological Information Processing / IBI-6 Cellular Structural Biology , D-52425 Jülich , Germany
4. Ruhr University Bochum, Protein Crystallography, Department of Biophysics, Universitätsstraße 150 , D-44780 Bochum , Germany
5. Ruhr University Bochum, Center for Protein Diagnostics (PRODI), Biospectroscopy , D-44780 Bochum , Germany
6. Max Planck Institute of Molecular Physiology , Crystallography and Biophysics Facility, D-44227 Dortmund , Germany