1. Department of Biochemistry, University of Illinois at Urbana−Champaign, Roger Adams Laboratory, 600 S. Mathews Ave., Urbana, Illinois 61801, United States
2. Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, 1206 W. Gregory Drive, Urbana, Illinois 61801, United States
3. Center for Biophysics and Computational Biology, University of Illinois at Urbana−Champaign, Roger Adams Laboratory, 600 S. Mathews Ave., Urbana Illinois 61801, United States
4. Department of Microbiology, University of Illinois at Urbana−Champaign, Chemical and Life Sciences Laboratory, 601 S. Goodwin Ave., Urbana, Illinois 61801, United States