1. Interfaculty Institute of Microbiology and Infection Medicine, Organismic Interactions Department, Cluster of Excellence 'Controlling Microbes to Fight Infections', Tübingen University, 72076 Tübingen, Germany
2. Department of Protein Evolution, Max Planck Institute for Biology, 72076 Tübingen, Germany
3. Plant Physiology Department, Institute of Biological Sciences, Rostock University, 18059 Rostock, Germany
4. Interfaculty Institute of Biochemistry, Tübingen University, 72076 Tübingen, Germany