Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada. map1@sfu.ca.|Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada. tva4@sfu.ca.|Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada. raymondl@sfu.ca.|Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada. brinkman@sfu.ca.