1. Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
2. Department of Physics, The University of Vermont, Burlington, Vermont 05408, United States
3. Department of Bioinformatics and Computational Biology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, United States
4. Department of Biology, University of Maryland, College Park, Maryland 20742, United States
5. Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
6. Center for Biological and Engineering Sciences, Sandia National Laboratories, Albuquerque, New Mexico 87185, United States