1. Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch , 301 University Boulevard, Galveston, TX 77555 , United States
2. Department of Microbiology and Immunology, The University of Texas Medical Branch , 301 University Boulevard, Galveston, TX 77555 , United States
3. Department of Pediatrics, The University of Texas Medical Branch , 301 University Boulevard, Galveston, TX 77555 , United States
4. Institute for Human Infections and Immunity, The University of Texas Medical Branch , 301 University Boulevard, Galveston, TX 77555 , United States
5. Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch , 301 University Boulevard, Galveston, TX , United States