1. Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis, St. Louis, Missouri 63110, United States
2. Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
3. McKelvey School of Engineering, Washington University in St. Louis, St. Louis, Missouri 63110, United States
4. Department of Biochemistry and Structural Biology and Center for Innovative Drug Discovery, School of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229, United States