Series and Focus

The volumes in the series, Methods in Molecular Biology, are conceived with the biochemist and molecular biologist in mind. The present book, Crystallographic Methods and Protocols, concentrates on the use of X-ray crystallography to solve the detailed three­-dimensional structures of proteins, nucleic acids, and their complexes.

Structure Determination Challenges

Such a structure determination is a major undertaking, demands expertise in a range of skills, and requires considerable resources. The biologically trained worker will probably first become involved when identifying an important scientific problem whose solution would benefit from a full structure. The protein or nucleic acid at issue must be sequenced and prepared to high purity in appropriate quantities, probably by either chemical synthesis for nucleic acids or genetic engineering for proteins.

Techniques and Goals

Crystallographic Methods and Protocols aims to give biologically trained workers an insight into the techniques used to crystallize their proteins, obtain the raw X-ray data, and solve and refine the structure. The aim of a crystal structure determination is to provide information that will solve biologically relevant problems; that process normally requires a high resolution structure.

Preparation and Challenges

The preparation of suitable crystals for a high resolution structure remains the major bottleneck in structure determination, and the effective application of appropriate genetic engineering and biochemical techniques in the initial stages pays a handsome dividend later. The production of suitable proteins by recombinant methods and the preparation of crystalline derivatives are covered by Skelly and Madden in Chapter 2. Before beginning the data collection required for a high resolution structure, a preliminary characterization of the crystals is carried out.