1. Departamento
de Biologı́a y Geologı́a, Fı́sica
y Quı́mica Inorgánica, E.S.C.E.T., Universidad Rey Juan Carlos, 28933 Móstoles, Madrid, Spain
2. Institute
of Biochemistry and Molecular Medicine, NCCR TransCure, University of Bern, Bühlstrasse 28, CH-3012 Bern, Switzerland
3. Laboratory
of Crystallography, ETH Zürich, Vladimir-Prelog-Weg 5, CH-8093 Zürich, Switzerland