1. Section Electron Microscopy, Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden 2333 ZC, Netherlands.
2. Molecular Virology Laboratory, Department of Medical Microbiology, Leiden University Medical Center, Leiden 2333 ZA, Netherlands.
3. Department of Structural Cell Biology of Viruses, Centre for Structural Systems Biology, Heinrich Pette Institute, Leibnitz Institute of Experimental Virology, 22607 Hamburg, Germany.
4. Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94143, USA.
5. Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94143, USA.
6. Department of Chemistry, MIN Faculty, Universität Hamburg, 20146 Hamburg, Germany.