1. Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, United States
2. Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, United States
3. Department of Chemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
4. Department of Chemistry, Saint Louis University, St. Louis, Missouri 63103, United States
5. Department of Chemistry, University of Rochester, Rochester, New York 14627, United States