1. Department
of Chemistry and Biology, Ryerson University, Toronto, Ontario M5B 2K3, Canada
2. Max Plank Institute for Biophysical Chemistry, 37077 Göttingen, Germany
3. Department
of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
4. Molecular
Structure and Function, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada