Resolution extension by image summing in serial femtosecond crystallography of two-dimensional membrane-protein crystals

Cecilia M. Casadei, Ching Ju Tsai, Anton Barty, Mark S. Hunter, Nadia A. Zatsepin, Celestino Padeste, Guido Capitani, W. Henry Benner, Sébastien Boutet, Stefan P. Hau-Riege, Christopher Kupitz, Marc Messerschmidt, John I. Ogren, Tom Pardini, Kenneth J. Rothschild, Leonardo Sala, Brent Segelke, Garth J. Williams, James E. Evans, Xiao Dan LiMatthew A Coleman, Bill Pedrini, Matthias Frank

Research output: Contribution to journalArticle

7 Scopus citations


Previous proof-of-concept measurements on single-layer two-dimensional membrane-protein crystals performed at X-ray free-electron lasers (FELs) have demonstrated that the collection of meaningful diffraction patterns, which is not possible at synchrotrons because of radiation-damage issues, is feasible. Here, the results obtained from the analysis of a thousand single-shot, room-temperature X-ray FEL diffraction images from two-dimensional crystals of a bacteriorhodopsin mutant are reported in detail. The high redundancy in the measurements boosts the intensity signal-to-noise ratio, so that the values of the diffracted intensities can be reliably determined down to the detector-edge resolution of 4'Å. The results show that two-dimensional serial crystallography at X-ray FELs is a suitable method to study membrane proteins to near-atomic length scales at ambient temperature. The method presented here can be extended to pump-probe studies of optically triggered structural changes on submillisecond timescales in two-dimensional crystals, which allow functionally relevant large-scale motions that may be quenched in three-dimensional crystals.

Original languageEnglish (US)
Pages (from-to)103-117
Number of pages15
StatePublished - Jan 1 2018
Externally publishedYes



  • free-electron lasers
  • membrane proteins
  • serial crystallography
  • two-dimensional crystals

ASJC Scopus subject areas

  • Chemistry(all)
  • Biochemistry
  • Materials Science(all)
  • Condensed Matter Physics

Cite this

Casadei, C. M., Tsai, C. J., Barty, A., Hunter, M. S., Zatsepin, N. A., Padeste, C., Capitani, G., Benner, W. H., Boutet, S., Hau-Riege, S. P., Kupitz, C., Messerschmidt, M., Ogren, J. I., Pardini, T., Rothschild, K. J., Sala, L., Segelke, B., Williams, G. J., Evans, J. E., ... Frank, M. (2018). Resolution extension by image summing in serial femtosecond crystallography of two-dimensional membrane-protein crystals. IUCrJ, 5, 103-117.