1. Biocentre Johannes-Gutenberg University Mainz 55128 Mainz Germany
2. Institute of Molecular Biology gGmbH 55128 Mainz Germany
3. Structural and Computational Biology Unit and Cell Biology and Biophysics Unit European Molecular Biology Laboratory Meyerhofstraße 1 69117 Heidelberg Germany
4. ARAXA Biosciences GmbH Meyerhofstraße 1 69117 Heidelberg Germany