1. Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
2. Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
3. National Center for Supercomputer Applications, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
4. Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109, United States
5. School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
6. Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States