Automated crystal mounting and data collection for protein crystallography

To increase the efficiency of diffraction data collection for protein cryst allographic studies, an automated system designed to store frozen protein c rystals, mount them sequentially, align them to the X-ray beam, collect com plete data sets, and return the crystals to storage has been developed. Advances in X-ray data collection technology including more brilliant X-ray sources, improved focusing optics, and faster-readout detectors have reduc ed diffraction data acquisition times from days to hours at a typical prote in crystallography laboratory [1, 2]. In addition, the number of high-brill iance synchrotron X-ray beam lines dedicated to macromolecular crystallogra phy has increased significantly, and data collection times at these facilit ies can be routinely less than an hour pier crystal. Because the number of protein crystals that may be collected in a 24 hr period has substantially increased, unattended X-ray data acquisition, including automated crystal m ounting and alignment, is a desirable goal for protein crystallography. The ability to complete X-ray data collection more efficiently should impact a number of fields, including the emerging structural genomics field [3], st ructure-directed drug design, and the newly developed screening by X-ray cr ystallography [4], as well as small molecule applications.