1. Department of Biochemistry and Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
2. Program in Chemical Biology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, Massachusetts 01605, United States
3. Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
4. Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, United States
5. James A. Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, United States