1. Department of Molecular and Cellular Biology, University of Utrecht, Utrecht
2. Unilever Research and Development Vlaardingen, Vlaardingen
3. CMBI, KUN, Nijmegen, The Netherlands
4. Architecture et Fonction des Macromolécules Biologiques, UMR 6098 CNRS and Universités Aix-Marseille I & II, Marseille, France