Lucia Banci1, Wolfgang Baumeister2, Udo Heinemann3, Gunter Schneider4, Israel Silman5, David I Stuart7 and Joel L Sussman6 
1
Centro Risonanze Magnetiche, University of Florence, Via Luigi Sacconi 6, Sesto Fiorentino (Florence) 50019, Italy
2
Max Planck Institute of Biochemistry, Am Klopferspitz 18a, Martinsried D-82152, Germany
3
Max-Delbrück-Center for Molecular Medicine, Robert-Roessle-Str 10, Berlin D-13125, Germany
4
Karolinska Institutet, Scheelevägen 2, Stockholm S-171 77, Sweden
5
Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
6
Department of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel
7
Division of Structural Biology, Oxford University, Oxford OX3 7BN, UK