1. Department of Biomolecular Nanotechnology
2. MESA+ Institute for Nanotechnology
3. University of Twente
4. 7500 AE Enschede
5. The Netherlands
6. Centro Nacional de Microbiología/ISCIII
7. Madrid
8. Spain
9. Department of Structure of Macromolecules
10. Centro Nacional de Biotecnología (CNB-CSIC)