Ideal values of bond angles and lengths used as external restraints are crucial for the successful
refinement of protein crystal structures at all but the highest of resolutions. The restraints in
common usage today have been designed based on the assumption that each type of bond or
angle has a...
Crystallographic studies of ligands bound to biological macromolecules (proteins and nucleic acids) represent an important source of information concerning drug-target interactions, providing atomic level insights into the physical chemistry of complex formation between macromolecules and ligands. Of the more than 115,000 entries extant in the Protein Data Bank (PDB) archive,...