1. Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, WA 98195, USA.
2. Graduate Program in Biological Physics, Structure, and Design, University of Washington, Seattle, WA 98195, USA.
3. Princess Margaret Cancer Centre, Toronto, Ontario M5G 1L7, Canada.
4. Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada.
5. Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada.
6. Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA.