1. Institute of Biochemistry, Department of Biology , ETH Zurich, Hönggerbergring 64, 8093 Zürich, Switzerland
2. Institute of Molecular Systems Biology, Department of Biology , ETH Zurich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland
3. Biomolecular NMR Spectroscopy Platform, ETH Zurich , Hönggerbergring 64, 8093 Zürich , Switzerland