1. Division of Tumor Virology, Dana-Farber Cancer Institute, Boston, MA 02115 and Department of Pathology, Harvard Medical School, Boston, MA 02115.
2. Department of Molecular Oncology and Virology, Roche Institute of Molecular Biology, Roche Research Center, Nutley, NJ 07110.
3. Department of Neurobiology, Harvard Medical School, Boston, MA 02115.
4. Microchemistry Facility, Harvard University, Cambridge, MA 02138.
5. Department of Chemistry, Harvard University, Cambridge, MA 02138.