1. Chemical and Physical Biology Program, Medical Scientist Training Program, Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37232, United States
2. Department of Chemistry, Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37232, United States
3. Departments of Pharmacology and Biomedical Informatics, Vanderbilt University, Nashville, Tennessee 37212, United States
4. Institute for Drug Discovery, Leipzig University Medical School, Leipzig SAC 04103, Germany