1. Department of Chemistry Duke University Durham NC 27708 USA
2. Current address: Ambagon Therapeutics Inc. 953 Indiana Street San Francisco CA 94107 USA
3. Department of Biochemistry Duke University School of Medicine Durham NC 27710 USA
4. Current address: Epigenetics & Stem Cell Biology Laboratory National Institute of Environmental Health Sciences Durham NC 27709 USA
5. Department of Pharmacology and Cancer Biology Duke University School of Medicine Durham NC 27710 USA