1. Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, USA
2. Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4, Canada
3. Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
4. Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
5. Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
6. Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
7. Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA