Structural biology techniques: X-ray crystallography, cryo-electron microscopy, and small-angle X-ray scattering

X-ray crystallography is one of the most commonly used techniques to characterize the three-dimensional (3D) structure of biological macromolecules. A critical step in the process of 3D structure determination of macromolecules by X-ray crystallography is the production of well-ordered, diffraction quality crystals. Other techniques do not present this limitation but rather study the biomolecules in solution, such as single-particle cryo-electron microscopy and small-angle X-ray scattering. We aim to provide graduate students or researchers working with metalloproteins with an overview on some of the methodologies available for the determination of the 3D structure of proteins, and what information can be extracted from these models.