Speaker: Yingssu Tsai, SSRL
Program Description
A goniometer-based experimental setup was developed for femtosecond diffraction experiments at LCLS in a collaboration between the Macromolecular Crystallography group at SSRL and the X-ray Pump Probe group at LCLS. This talk will focus on efforts to determine radiation-damage free structures of cytochrome ba3 oxidase, a protein that catalyzes the reduction of oxygen, and myoglobin, an oxygen binding protein. The catalytic metal center of cytochrome ba3 crystals is acutely radiation sensitive and undergoes significant reduction during a single X-ray exposure at the synchrotron. The machinery installed in the XPP hutch was based on developments in beamline automation at BL12-2 at SSRL. A specialized sample mounting grid was designed for holding multiple crystal samples at once, allowing for faster data collection. The beamline user interface was extended to handle data collection from the sample mounting grid. This goniometer setup is beneficial for multiple biological targets by providing an efficient way of data collection while minimizing the number of samples needed for the experiment.
