1. Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
2. Department
of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6321, United States
3. Electron
Microscopy Resource Laboratory, Department of Biochemistry and Biophysics,
Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6082, United States
4. Department
of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6391, United States
5. Department
of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6396, United States
6. Division
of Infectious Diseases, Department of Internal Medicine, Program in
Immunology, University of Michigan, Ann Arbor, Michigan 48109, United States
7. Institute
of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians-University, Veterinärstrasse 13, 80539 Munich, Germany
8. Institute
of Computational Molecular Science, Temple University, Philadelphia, Pennsylvania 19122, United States