New light on protein structure: Macromolecular crystallography

X-ray diffraction is the method of choice to determine structural information from biological mac romolecules to atomic resolution. This technique depends on the availability of single crystals of protein, which are notoriously difficult to produce. It can take months or even years to find crystal lization conditions capable of producing crystals with sufficient diffraction quality. During the last few years the field of MX (macromolecular crystallography) has undergone considerable change and most of the steps from protein expression to structure solution have been automated, speeding up the process significantly. Facilities such as Diamond Light Source, the new UK synchrotron radia tion source in Oxfordshire, have been developed to incorporate new automation technologies and Diamond will provide an important user resource for XRD (X-ray diffraction) experiments on crystals of biological macromolecules. Furthermore, in collaboration with Professor So Iwata (Imperial College and Diamond Light Source) and funded by the Wellcome Trust, Diamond Light Source is developing a laboratory dedicated specifically to solving the structure of membrane proteins, the crystallization of which poses a particular problem to the crystallographer.