1. Department of Biochemistry, University of Washington, Seattle, Washington 98195,
United States
2. Howard Hughes Medical
Institute, University of Washington, Seattle,
Washington 98195,
United States
3. Department
of Microbiology, University of Washington, Seattle, Washington 98195,
United States
4. Department of Biochemistry & Molecular Medicine, University of California, Davis, California, United States
5. Department of Chemistry, University of California, Davis, California, United
States
6. Genome Center, University of California, Davis, California, United
States