1. Department
of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
2. Protein
Crystallography Facility and Department of Biochemistry, University of Iowa, Iowa City, Iowa 52242, United States
3. Department
of Chemistry and the Lise Meitner-Minerva Center of Computational
Quantum Chemistry, Bar-Ilan University, Ramat-Gan 5290002, Israel