1. Department
of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstrasse
5-13, 81377 München, Germany
2. Munich Center for Integrated Protein Science, Butenandtstrasse 5-13, 81377 München, Germany
3. Department
of Molecular and Cell Biology, University of California, Berkeley, California 94720, United States
4. Helen
Wills Neuroscience Institute, University of California, Berkeley, California 94720, United States
5. Physical
Bioscience Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States