1. Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, GA 30310, USA
2. School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
3. Division of Molecular and Cellular Pathology, Department of Pathology, The University of Alabama at Birmingham, Birmingham, AL 35233, USA
4. Department of Biochemistry Emory, University School of Medicine, Atlanta, GA 30329, USA