1. Department of Chemistry and the Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, California 92037, United States
2. Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
3. Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States