1. Department of Chemical Biology and Drug Discovery Utrecht Institute for Pharmaceutical Sciences Utrecht University 3584 CG Utrecht The Netherlands
2. Department of Medical Microbiology Amsterdam Institute for Infection and Immunity Amsterdam UMC University of Amsterdam 1105AZ Amsterdam The Netherlands
3. Department of Integrative Structural and Computational Biology The Scripps Research Institute La Jolla CA, 92037 USA
4. Department of Microbiology and Immunology Weill Medical College of Cornell University New York NY 10021 USA
5. Complex Carbohydrate Research Center University of Georgia Athens GA 30602 USA
6. Bijvoet Center for Biomolecular Research Utrecht University Utrecht The Netherlands
7. Chemistry Department University of Georgia Athens GA 30602 USA