1. Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, Iowa 50011, United States
2. Department of Chemistry, University of California-Davis, Davis, California 95616, United States
3. Department of Biochemistry and Molecular Medicine, University of California-Davis, Davis, California 95616, United States
4. Genome Center, University of California-Davis, Davis, California 95616, United States