1. Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037
2. Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
3. Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037
4. Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461
5. The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037