1. Institute of Microbiology, Technical University Braunschweig, Spielmannstrasse 7, Braunschweig D-38106, Germany
2. Division of Structural Biology, Helmholtz Centre for Infection Research, Inhoffenstraße 7, Braunschweig D-38124, Germany
3. Department of Biotechnology, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa
4. Department of Biomolecular Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
5. Department of Bioengineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan