1. Department of Biochemistry, University of Leicester, University Road, Leicester LE1 7RH, U. K., Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QT, U. K., Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U. K., Protein and Nucleic Acid Laboratory, University of Leicester, Centre for Mechanisms of Human Toxicity, Lancaster Road, Leicester LE1 9HN, U.K., and Laboratory of Microbiology and Biotechnology, Institute of...