1. Department of Physics, University of Toronto, Toronto, Ontario M5G 1X8, Canada
2. Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
3. Molecular Medicine Program, Hospital for Sick Children, Toronto, Ontario M5S 1A8, Canada
4. Department of Biochemistry, University of Toronto, Toronto, Ontario M5G 1X8, Canada
5. Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105, United States
6. Departments of Chemistry, Bioengineering, Chemical and Biomolecular Engineering University of California, Berkeley, California 94720, United States