1. Midwest Center for Structural Genomics, Argonne National Laboratory; Argonne Illinois 60439
2. Department of Biosciences; Structural Biology Center; Argonne National Laboratory; Argonne Illinois 60439
3. Center for Structural Genomics of Infectious Diseases; University of Chicago; Chicago Illinois 60637
4. Howard Taylor Ricketts Laboratory; Argonne National Laboratory; Argonne Illinois 60439
5. Department of Microbiology; University of Chicago; Chicago Illinois 60637