1. Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.
2. Biochemistry Center of Heidelberg University, Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany.
3. Department of Chemistry, Chemical Biology and Biomedical Engineering, Stevens Institute of Technology, 507 River Street, Hoboken, NJ 07030, USA.
4. Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada.
5. Cell Biology and Biophysics Unit, EMBL, Heidelberg, Germany.