1. Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
2. Institute of Physics, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
3. Department of Physics, University of Konstanz, Universitätstrasse 10, 78457 Konstanz, Germany
4. Institute of Molecular Systems Biology, ETH Zurich, Wolfgang Pauli-Strasse 16, 8093 Zürich, Switzerland