1. Department of Medical Microbiology and Immunology, University of Wisconsin—Madison, 1550 Linden Drive, Madison, Wisconsin 53706
2. Department of Biochemistry, University of Wisconsin—Madison, 433 Babcock Drive, Madison, Wisconsin 53706
3. Department of Molecular Biology and Microbiology, Tufts University School of Medicine, 150 Harrison Ave., Boston, Massachusetts 02111
4. Morgridge Institute for Research, 330 North Orchard Street, Madison, Wisconsin 53715