1. Departments of Biochemistry, Molecular Biology, and Cell Biology and of Chemistry, Northwestern University, Evanston, Illinois 60208, Department of Biological, Chemical and Physical Sciences, Roosevelt University, Chicago, Illinois 60605, Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, and Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine,...