1. Gene Targeted Drug Design Research Group, School of Pharmacy and Biomedical Science, University of Portsmouth, Portsmouth PO1 2DT, U.K., CRC Drug DNA Interactions Research Group, Department of Oncology, University College London Medical School, London W1P 8BT, U.K., School of Biological Sciences, University of East Anglia, Norwich NR4 7JT, U.K., and CRC Biomolecular Structure Unit, The Institute of Cancer Research, Sutton, Surrey SM2 5NG, U.K.