1. Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, 1010 Vienna, Austria
2. Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, 1000 Ljubljana, Slovenia
3. European Molecular Biology Laboratory (EMBL) Grenoble, 38000 Grenoble, France
4. Department of Chemistry, University of Pavia, 27100 Pavia, Italy