Resolution extension by image summing in serial femtosecond crystallography of two-dimensional membrane-protein crystals
Category
Published on
Type
journal-article
Author
Cecilia M. Casadei and Ching-Ju Tsai and Anton Barty and Mark S. Hunter and Nadia A. Zatsepin and Celestino Padeste and Guido Capitani and W. Henry Benner and Sébastien Boutet and Stefan P. Hau-Riege and Christopher Kupitz and Marc Messerschmidt and John I. Ogren and Tom Pardini and Kenneth J. Rothschild and Leonardo Sala and Brent Segelke and Garth J. Williams and James E. Evans and Xiao-Dan Li and Matthew Coleman and Bill Pedrini and Matthias Frank
Citation
Casadei, C.M. et al., 2018. Resolution extension by image summing in serial femtosecond crystallography of two-dimensional membrane-protein crystals. IUCrJ, 5(1), pp.103–117. Available at: http://dx.doi.org/10.1107/s2052252517017043.
Abstract
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.
DOI
Funding
NSF-STC Biology with X-ray Lasers (NSF-1231306)