1. The Donnelly Centre, University of Toronto, Toronto, Ontario M5S 3E1, Canada.
2. Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
3. Department of Biochemistry, Stanford Genome Technology Center, Stanford University, Palo Alto, CA 94304, USA.
4. Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Sciences Center, College Station, TX 77843–1114, USA.
5. School of Pharmacy, University of Waterloo, Kitchener, Ontario N2G 1C5, Canada.
6. Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada.
7. Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
8. Cell Biology Program, Hospital for Sick Children, University of Toronto, Toronto, Ontario M5G 1X8, Canada.
9. Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
10. Department of Pharmaceutical Sciences, Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada.
11. Institut des Sciences de la Vie, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium.
12. Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada.
13. Laboratoire d'Enzymologie et Biochimie Structurales, Centre National de la Recherche Scientifique (CNRS), Gif-sur-Yvette, France.