1. Medical Research Council Laboratory of Molecular Biology; Francis Crick Avenue Cambridge CB2 0QH UK
2. Department of Biology/Centre for Applied Synthetic Biology; Concordia University; 7141 Rue Sherbrooke Montreal H4B 1R6 Canada
3. Division of Structural Biology; The Institute of Cancer Research; Chester Beatty Laboratories); 237 Fulham Road London SW3 6JB UK
4. Rega Institute; KU Leuven; Minderbroedersstraat 10 3000 Leuven Belgium
5. Institute of Systems and Synthetic Biology; Université Evry; 5 rue Henri Desbrueres 91030 Evry Cedex France