1. Center for Plant Molecular Biology, University of Tübingen, 72076 Tübingen, Germany
2. Medical Research Council Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, United Kingdom
3. Zentrum für Datenverarbeitung, University of Tübingen, 72074 Tübingen, Germany
4. Department of Biology, University of Tübingen, 72076 Tübingen, Germany
5. Department of Chemistry, University of Zürich, 8057 Zurich, Switzerland
6. Department of Pharmacology, Howard Hughes Medical Institute, University of Washington, Seattle, Washington 98195
7. Department of Plant Biochemistry, Georg-August-University Göttingen, 37077 Göttingen, Germany
8. Plant-Microbe Interactions, Department of Biology, Utrecht University, 3508 TB Utrecht, The Netherlands