1. Department
of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
2. Department
of Crystallography and Structural Biology, Instituto de Química-Física “Rocasolano”, Consejo Superior de Investigaciones Científicas, Madrid, Spain
3. Freimann
Life Sciences Center and Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States