1. Department of Chemistry, Wichita State University, Wichita, KS 67260, USA.
2. Department of Microbiology and Immunology, University of Iowa, Iowa City, IA 52242, USA.
3. Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA.
4. Department of Pathology, University of Iowa, Iowa City, IA 52242, USA.
5. Protein Structure Laboratory, University of Kansas, Lawrence, KS 66045, USA.
6. NYX, New York Structural Biology Center, Upton, NY 11973, USA.