1. Department of Biochemistry, University of Toronto, Toronto, Ontario M5G 1M1, Canada
2. Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
3. Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
4. Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
5. Ontario Cancer Institute/Princess Margaret Hospital, Toronto, Ontario M5G 1L7, Canada
6. Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada