Affiliation: | 1. Department of Biology, Washington University, St. Louis, MO 63130, USA;2. Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA;3. Department of Chemistry, University of California, Davis, 1 Shields Avenue, Davis, CA 95616, USA;4. Department of Bacteriology, University of Wisconsin, Madison, WI 53706, USA |