Institution: | From the ‡Structural Biochemistry Group, Institute of Structural and Molecular Biology, University of Edinburgh, Michael Swann Building, King''s Buildings, Mayfield Road, Edinburgh EH9 3JR, Scotland, United Kingdom and ;the §Research Unit for Tropical Diseases, de Duve Institute and Laboratory of Biochemistry, Université Catholique de Louvain, Avenue Hippocrate 74, B-1200 Brussels, Belgium |