Strategies for Improving Crystallization Success Rates

The production of crystals suitable for high-resolution structure determination is still one of the major bottlenecks in the structure determination process. This is especially true in structural genomics (SG) consortia, where the implementation of protein-specific purification and optimization strategies is not readily implemented into the structure determination workflow. This chapter describes four strategies that have been implemented by a number of SG groups to increase the number of protein targets that resulted in atomic resolution structures: (1 ) orthologue screening; (2 ) the use of 1D 1 H NMR spectroscopy to screen for the folded state of a protein prior to crystallization; (3 ) deletion constructs generation, in which regions of the target protein predicted to be disordered are omitted from the construct, to maximize the likelihood of crystal formation; and (4 ) crystallization optimum solubility screening to identify more suitable buffers for a given protein. The imple mentation of these strategies can lead to a substantial increase in the number of protein structures solved. Finally, because these strategies do not require the implementation of expensive robotics, they are highly applicable not only for the SG community but also for academic laboratories.