1. Genome Sciences and Technology Program, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
2. Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
3. Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
4. Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada