About the Authors
Emory Vaccine Center and Department of Microbiology & Immunology, Emory University School of Medicine, Atlanta, Georgia, United States of America
The authors have declared that no competing interests exist.
Conceived and designed the experiments: AS SS. Performed the experiments: AS. Analyzed the data: AS SS. Contributed reagents/materials/analysis tools: JH. Wrote the paper: AS SS. Helped AS in the early stages of designing experiments, provided specific mutants, and provided help with some experiments: JH.