1. Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), 71, Avenue des Martyrs, F-38044 Grenoble, France.
2. Structural Biology and NMR Laboratory, the Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, 2200 Copenhagen, Denmark.
3. Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, Germany.
4. European Molecular Biology Laboratory, 38042 Grenoble, France.