1. Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105, United States
2. Medicinal Research Laboratories, Shionogi & Co., Ltd., 12-4, Sagisu 5-Chome, Fukushima-ku, Osaka, Japan
3. Department of Biochemistry and Biophysics, University of California at San Francisco, 600 16th Street, San Francisco, California 94143, United States