Symmetry in crystallography

Abstract

Most biologists come into contact with crystallography when they want to study the structure of a biological molecule. They may want to know whether both enantiomers of a drug molecule are present in a drug preparation. If the molecule is a protein, they may enquire whether the three-dimensional (3D) structure throws light on to the oligomeric state of the protein or the 3D arrangement of the active site of an enzyme. To investigate these matters, some knowledge of the theory of both molecular symmetry and crystal symmetry is essential. This article is an overview of this fascinating aspect of biological structure. © Biochemical Society.