7 Å resolution in protein two-dimensional-crystal X-ray diffraction at Linac Coherent Light Source Academic Article uri icon

abstract

  • Membrane proteins arranged as two-dimensional crystals in the lipid environment provide close-to-physiological structural information, which is essential for understanding the molecular mechanisms of protein function. Previously, X-ray diffraction from individual two-dimensional crystals did not represent a suitable investigational tool because of radiation damage. The recent availability of ultrashort pulses from X-ray free-electron lasers (XFELs) has now provided a means to outrun the damage. Here, we report on measurements performed at the Linac Coherent Light Source XFEL on bacteriorhodopsin two-dimensional crystals mounted on a solid support and kept at room temperature. By merging data from about a dozen single crystal diffraction images, we unambiguously identified the diffraction peaks to a resolution of 7 Å, thus improving the observable resolution with respect to that achievable from a single pattern alone. This indicates that a larger dataset will allow for reliable quantification of peak intensities, and in turn a corresponding increase in the resolution. The presented results pave the way for further XFEL studies on two-dimensional crystals, which may include pump-probe experiments at subpicosecond time resolution.

authors

  • Pedrini, Bill
  • Tsai, Ching-Ju
  • Capitani, Guido
  • Padeste, Celestino
  • Hunter, Mark S
  • Zatsepin, Nadia A
  • Barty, Anton
  • Benner, W Henry
  • Boutet, Sébastien
  • Feld, Geoffrey K
  • Hau-Riege, Stefan P
  • Kirian, Richard A
  • Kupitz, Christopher
  • Messerschmitt, Marc
  • Ogren, John I
  • Pardini, Tommaso
  • Segelke, Brent
  • Williams, Garth J
  • Spence, John CH
  • Abela, Rafael
  • Coleman, Matthew
  • Evans, James E
  • Schertler, Gebhard FX
  • Frank, Matthias
  • Li, Xiao-Dan

publication date

  • 2014