Protein crystal structures are three-dimensional atomic models of proteins obtained by crystallographic analysis of protein crystals. A protein crystal contains a periodic array of ordered macromolecules, and X-ray diffraction from this array provides measured reflection intensities that are used to calculate electron-density maps. An atomic model is built and refined against these experimental data to specify the coordinates, occupancies, and atomic displacement parameters of the protein and any resolved ligands, cofactors, ions, solvent molecules, or ordered structural components [1][2]. The resulting structure defines the conformation and packing of the protein molecules within the crystallographic asymmetric unit and relates them through crystallographic symmetry to generate the unit cell and full crystal lattice [1][3]. Model interpretation incorporates experimental resolution, electron-density quality, stereochemical restraints, crystallographic residuals, and cross-validation statistics to quantify agreement between the atomic model and diffraction data [3][4].
- X-ray crystallography
- protein crystals
- electron density
- macromolecular structure
🔵 Crystal structures of chemical compounds • 🟣 Inorganic Chemistry • 🟡 Chemistry • 🔴 Physical
References
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- Axel T. Brünger; Free R Value: a Novel Statistical Quantity for Assessing the Accuracy of Crystal Structures. Nat. 1992, 355, 472-475, 10.1038/355472a0.
- Ivan G. Shabalin; Przemyslaw J. Porebski; Wladek Minor; Refining the Macromolecular Model – Achieving the Best Agreement with the Data from X-ray Diffraction Experiment. Crystallogr. Rev. 2018, 24, 236-262, 10.1080/0889311x.2018.1521805.
- Vladimir Timofeev; Valeriya Samygina; Protein Crystallography: Achievements and Challenges. Cryst. 2023, 13, 71, 10.3390/cryst13010071.