1. Department of Microbiology and Immunology, Louisiana State University Health Sciences Center Shreveport, Shreveport, Louisiana, USA
2. Division of Biological Sciences, University of Montana, Missoula, Montana, USA
3. Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, Montana, USA
4. Biochemistry and Biophysics Program, University of Montana, Missoula, Montana, USA
5. GSK, Siena, Italy
6. GSK, Rockville, Maryland, USA
7. Cellular, Molecular and Microbial Biology Program, University of Montana, Missoula, Montana, USA
8. University of Naples Federico II, Naples, Italy