1. Resolution extension by image summing in serial femtosecond crystallography of two-dimensional membrane-protein crystals
- Author
-
Casadei, Cecilia M, Tsai, Ching-Ju, Barty, Anton, Hunter, Mark S, Zatsepin, Nadia A, Padeste, Celestino, Capitani, Guido, Benner, W Henry, Boutet, Sébastien, Hau-Riege, Stefan P, Kupitz, Christopher, Messerschmidt, Marc, Ogren, John I, Pardini, Tom, Rothschild, Kenneth J, Sala, Leonardo, Segelke, Brent, Williams, Garth J, Evans, James E, Li, Xiao-Dan, Coleman, Matthew, Pedrini, Bill, and Frank, Matthias
- Subjects
Inorganic Chemistry ,Chemical Sciences ,Physical Sciences ,Bioengineering ,serial crystallography ,free-electron lasers ,membrane proteins ,two-dimensional crystals ,Atomic ,Molecular ,Nuclear ,Particle and Plasma Physics ,Condensed Matter Physics ,Physical Chemistry (incl. Structural) ,Physical chemistry ,Condensed matter physics - 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.
- Published
- 2018