1. Department
of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
2. Radboud University, Institute for Molecules and
Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands
3. University of Amsterdam, Science
Park 904, 1098XH Amsterdam, The Netherlands
4. Department
of Cell and Developmental Biology and Program in Structural Biology
and Biochemistry, University of Colorado Health Sciences Center, Denver, Colorado 80045, United States