1. Howard Hughes Medical Institute,
Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk
Institute for Biological Studies, 10010 North Torrey Pines Road, La
Jolla, California 92037
2. Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506
3. The Salk Institute for Biological Studies, Molecular and Cell Biology Laboratory, 10010 North Torrey Pines Road, La Jolla, California 92037
4. Xenobe Research Institute, 3371 Adams Avenue, San Diego, California 92116