1. Department
of New Materials and Biosystems, Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, D-70569 Stuttgart, Germany
2. Department
of Biophysical Chemistry, University of Heidelberg, Im Neuenheimer
Feld 253, D-69120 Heidelberg, Germany
3. Institute
for Advanced Study (IAS) and Center of Integrated Protein Science
(CIPSM), Department Chemie, Technische Universität München, Lichtenbergstr.
4, Garching D-85747, Germany