1. Department of Biochemistry, University of Illinois at Urbana−Champaign, 600 South Mathews Ave., Urbana, Illinois 61801, United States
2. Department of Chemistry, University of Illinois at Urbana−Champaign, 600 South Mathews Ave., Urbana, Illinois 61801, United States
3. Carle Illinois College of Medicine, 807 South Wright Street, Champaign, Illinois 61820, United States
4. Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, 1206 West Gregory Dr., Urbana, Illinois 61801, United States
5. Arnold and Mabel Beckman Institute, University of Illinois at Urbana−Champaign, 405 North Mathews Ave., Urbana, Illinois 61801, United States