Macromolecular Structural Biology

The course is focused on the 3D structure determination and analysis of proteins by using biocrystallographic, single particle cryo-EM and bioinformatic techniques. Experimental techniques for protein crystal growth will be described in details (including practicals in the bio-crystallography lab), with application to soluble and membrane proteins. X-ray diffraction on protein crystals and solution samples (SAXS) will be treated extensively (X-ray sources, synchrotron light, atomic scattering factors, structure factors, the "phase problem", phasing by molecular replacement and heavy atoms, crystallographic refinement). Protein model validation techniques will be analyzed, together with the main features of the Protein Data Bank. The theoretical basis and the practical applications of single-particle cryo-EM techniques will be treated, with special focus on sample preparation, transmission electron microscope anatomy, data acquisition and data processing. At the end of the lectures and of the practical sessions the students will be able to design and run experiments for crystal growth, electron microscopy sample preparation, processing of data for both techniques. They will also gain a critical view on the design and execution of research experiments in the structural biology context, aiming at understanding structure, function, interactions and modifications that characterize proteins in living cells.