1. Biomedical Center - BMC, Metabolic Biochemistry, Ludwig-Maximilians University, Munich 80539, Germany
2. Institute for Medical Physics and Biophysics, Leipzig University, Härtelstr. 16-18, D-04107 Leipzig, Germany
3. Department of Biochemistry and Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
4. German Center for Neurodegenerative Diseases (DZNE)−Munich, Feodor-Lynen-Str. 17, D-81377 Munich, Germany