5.4 X-ray crystallography
X-ray crystallography is a method for determining crystalline 3D structures of protein. Crystallized samples are exposed to X-rays, and the resulting patterns yield information about repeating unit sizes and crystal packing symmetry. This technique is applied to study various processes, including protein-DNA complexes, virus systems, and immunological functions. Moreover, it provides valuable insights into enzyme mechanisms, drug development, mutagenesis, and protein-ligand interactions [61].