Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland.|Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland.|Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland.|Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland.|Laboratory of Biomolecular Research, Paul Scherrer Institute, Villigen, Switzerland.