1. Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
2. Carl R.
Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
3. Boyce Thompson
Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
4. Department of Microbiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States