1. Department
of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109-1048, United States
2. Department
of Structural Biology, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105, United States
3. Department
of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee 38163, United States
4. Department
of Molecular Medicine, University of South Florida, Tampa, Florida 33612, United States
5. Institute
for Biological Instrumentation, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia