1. Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland 20892, United States
2. Departments of Biophysics and Microbiology, UT Southwestern Medical Center, Dallas, Texas 75390, United States
3. Office of Intramural Research, Center for Information Technology, National Institutes of Health, Bethesda, Maryland 20892, United States