1. Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, United States
2. Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
3. Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
4. Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
5. Department of Biophysics, Department of Biological Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
6. Howard Hughes Medical Institute, Baltimore, Maryland 21205, United States