1. Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg 85 764, Germany
2. Center for Integrated Protein Science Munich, Department Chemie, TU München, Garching 85748, Germany
3. Institute of Virology, Helmholtz Zentrum München, Neuherberg 85 764, Germany
4. Research Unit Cellular Signal Integration, Helmholtz Zentrum München, Neuherberg, 85 764, Germany
5. CEITEC - Central European Institute of Technology, Masaryk University, Brno 62 500, Czech Republic
6. EMBL Heidelberg, Heidelberg 69 117, Germany