1. Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
2. Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06520, USA
3. Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT 05405, USA
4. Department of Chemistry, Yale University, New Haven, CT 06520, USA
5. Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA