Protein structures at atomic resolution

Publisher Summary This chapter deals with the protein structures at atomic resolution. The number of very-high resolution structures currently deposited in the PDB clearly shows that protein crystals diffracting to atomic resolution are becoming less rare. Although the primary requirement is the ability of a macromolecule to form a highly ordered crystal, the very significant factor in the recent explosion of the atomic resolution analyses is the progress in all involved techniques. The availability of convenient and quick protein-purification methods, efficient crystal-growth screening conditions, convenient crystallization chambers that employ only small amounts of sample, and sometimes mechanisms (robots) to automate the setting up of crystallization trials all contribute to these successes. Moreover, the methods of protein purification and crystal growth, availability of bright synchrotron beam lines, and progress in software used in all stages of the analysis make such projects more tractable. The enhanced accuracy of the resulting models and the possibility of describing very fine structural features are very important for better understanding of the chemistry responsible for the biological properties of macromolecules, which is the ultimate goal of structural biology.