[...]...x Contents 9 Combining Cryo-EM and X-ray Crystallography to Study Membrane Protein Structure and Function Werner Kühlbrandt 93 10 Molecular Mechanisms of DNA Polymerase Clamp Loaders 103 Brian Kelch, Debora Makino, Kyle Simonetta, Mike O’Donnell, and John Kuriyan 11 Electron Microscopy of Macromolecular Machines 115 Helen R Saibil 12 Assembly and Function of... T.L Blundell (*) • D.Y Chirgadze Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK e-mail: tom@cryst.bioc.cam.ac.uk M.A Carrondo and P Spadon (eds.), Macromolecular Crystallography, NATO Science for Peace and Security Series A: Chemistry and Biology, DOI 10.1007/978-94-007-2530-0_1, © Springer Science+Business Media B.V 2012 1 2 Q Wu et al SV SE SAXS SPR ITC... Weizmann Institute of Science, Rehovot 76100, Israel Jordi Querol Instituto de Biología Molecular de Barcelona (CSIC-Parc Cientific de Barcelona), Baldiri i Reixac 10, Barcelona 08028, Spain Helen R Saibil Crystallography, and Institute of Structural and Molecular Biology, Birkbeck College, University of London, Malet St, London WC1E 7HX, UK, h.saibil@mail.cryst.bbk.ac.uk Elisabeth Sauer-Eriksson Department... available from different companies, e.g Hagel [30], Table 8.3.4 Prepacked Superdex 75 or 200 5/150 GL columns (GE healthcare), which have become available recently, may be useful for structural studies of macromolecular complexes because a small volume of a sample can run in a very short time without diluting samples 1.2.3 Biophysical Methods 1.2.3.1 Circular Dichroism Circular dichroism (CD) arises from... macromolecules [79, 80], and to provide structural information of flexible and disordered macromolecules [4] SAXS observes randomly orientated macromolecules in solution; therefore, in a way that differs from X-ray crystallography, the scattering intensity is averaged over orientation Scattering profiles can be inverse Fourier transformed to the distance distribution function, shapes of which directly reflect the shapes .