1. Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada
2. Centre for Structural Biology, McGill University, Montreal, Quebec H3G 0B1, Canada
3. Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
4. Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
5. Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
6. Department of Physics, The Ohio State University, Columbus, OH 43210, USA
7. Department of Chemistry & Biochemistry, Division of Hematology, The Ohio State University, Columbus, OH 43210, USA