1. Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, Laboratory of Cell Biology, NCI, National Institutes of Health, Bethesda, Maryland 20892, Protein Expression Laboratory, National Institute of Arthritis, Musculoskeletal, and Skin Diseases, National Institutes of Health, Bethesda, Maryland 20892, Laboratory of Immunology, NIAID, National Institutes of Health, Bethesda, Maryland 20892, and Department of Chemistry, University of Georgia, Athens, Georgia 30602