1. Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843.
2. Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts 02115
3. Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105
4. Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843