Electron crystallography determines ordered molecular or atomic structure using electrons interacting with a crystalline specimen. Electron diffraction and suitably resolved electron images provide complementary constraints on a structural model. The periodic order supplies repeated information; interpreting that information still requires a model of scattering and image formation.
An important biological application resolved the alpha/beta tubulin heterodimer. Zinc-induced tubulin sheets provided an ordered specimen for a model reported at angstrom resolution. The resulting structure distinguished the two related protein subunits and their different nucleotide environments.[ref]
Structure of the alpha beta tubulin dimer by E. Nogales and others. Nature 391 (1998), 199–203; abstract and structural deposition 1TUB: electron crystallography of zinc-induced sheets.
The specimen geometry matters. An ordered sheet is not the same object as an isolated microtubule in a living cell, even when its molecules reveal features relevant to microtubule assembly. The structural experiment answers questions about the molecular arrangement under its preparation conditions; biological interpretation then connects that arrangement to other observations.
Resolution also differs from the size of the object. A sheet may extend over many molecular repeats while the data constrain features on the angstrom scale. Quoting a nominal resolution does not mean every atom is independently located with that exact uncertainty or that every flexible region is equally well resolved.
Electron crystallography belongs to the wider family of electron microscopy and crystallography methods, but should not be used as a synonym for every electron micrograph. A dark spot, an image of a cellular outline and a diffraction-constrained molecular model are different types of evidence.
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Electron crystallography is a scientific technique used to determine the atomic and molecular structures of crystalline materials using electron diffraction. This method takes advantage of the wave nature of electrons, which can provide high-resolution structural information about materials thanks to their short wavelengths compared to X-rays. The key aspects of electron crystallography include: 1. **Electron Diffraction**: When a beam of electrons is directed at a crystalline sample, the electrons are scattered by the atoms in the crystal lattice.
Crystallography determination with a transmission electron microscopy instead of the more classical X-ray crystallography.