1. Division of Structural and Computational Biology, School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Fax: (+65) 6791‐3856
2. Current address: Department of Biological Chemistry and Molecular Pharmacology, Immune Disease Institute, Harvard Medical School, Center for Life Science Building, 3 Blackfan Circle, Boston 02115 (USA)
3. Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne (Switzerland)
4. Institute of Inorganic Chemistry, University of Vienna, Waehringer Street 42, 1090 Vienna (Austria)