1. Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
2. Novartis-Berkeley Translational Chemical Biology Institute, Berkeley, California 94720, United States
3. Innovative Genomics Institute, Berkeley, California 94720, United States
4. Novartis Biomedical Research, Emeryville, California 94608, United States
5. Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, United States