1. Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
2. Division of Infectious Diseases, Mayo Clinic, Rochester, MN 55902, USA.
3. Department of Internal Medicine, Mayo Clinic, Rochester, MN 55902, USA.
4. Department of Molecular Medicine, Mayo Clinic, Rochester, MN 55902, USA.