Institution: | † Department of Chemistry and Biochemistry, University of California-San Diego, La Jolla, California ‡ Division of Biological Sciences, University of California-San Diego, La Jolla, California § Department of Biochemistry and Cell Biology, Rice University, Houston, Texas ¶ Department of Plant Pathology, University of Kentucky, Lexington, Kentucky ‖ Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts |