1. Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, United States
2. Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
3. Department of Molecular and Cell Biology, University of Connecticut, 91 N. Eagleville Road, Storrs, Connecticut 06269, United States
4. Department of Chemistry and Biophysics Program, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States