1. Department
of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
2. Department
of Biomedical Engineering and Center for Computational Medicine and
Bioinformatics, University of Michigan, Ann Arbor, Michigan 48109, United States
3. Institut
für Organische Chemie, Universität Tübingen, 72076 Tübingen, Germany