1. Department of Biochemistry
and Molecular Biology, The Pennsylvania State University, 401 Althouse Laboratory, University Park, Pennsylvania 16802, United States
2. Department
of Molecular and Cell Biology, University of California, Berkeley, #3370, 375E Li Ka Shing Center, Berkeley, California 94720, United States
3. Department of Microbiology and Immunology,
Microbiology Research Facility, University of Minnesota, Rm4-115, 689 23rd Ave. SE, Minneapolis, Minnesota 55455, United States