1. Department of Computer Science, Duke University, Durham, North Carolina 27708, United States
2. Program in Computational Biology and Bioinformatics, Duke University, Durham, North Carolina 27708, United States
3. Department of Biochemistry & Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755, United States
4. Department of Biochemistry, Duke University, Durham, North Carolina 27710, United States
5. Department of Chemistry, Duke University, Durham, North Carolina 27710, United States