1. Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405
2. Research Group Translational Structural Biology, German Center for Neurodegenerative Diseases, Göttingen 37075, Germany
3. Department of Bioengineering, McGill University, Montréal, QC H3A 0C3, Canada
4. Department for NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry 37077 Göttingen, Germany