1. Department of Biochemistry and Molecular Biology, Penn State University, University Park, Pennsylvania 16802, United States
2. Graduate Program in Molecular, Cellular, and Integrative Biosciences, Penn State University, University Park, Pennsylvania 16802, United States
3. Department of Microbiology, University of Georgia, Athens, Georgia 30602, United States
4. Department of Chemistry, Penn State University, University Park, Pennsylvania 16802, United States