1. Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, Michigan 48109, United States
2. Department of Chemistry, Duke University, 124 Science Drive, Durham, North Carolina 27705, United States
3. Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
4. Wake Forest School of Medicine, 475 Vine Street, Winston Salem, North Carolina 27101, United States
5. Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California 92037, United States