Anomalous signal from S atoms in protein crystallographic data from an X-ray free-electron laser

Acta Cryst. (2013). D69, 838-842 (http://doi.org/mt9)

Serial femtosecond crystallography (SFX) using free-electron lasers (FELs) allows protein structures to be solved from nano- to micrometer-sized crystals using femtosecond pulses. However, SFX data collection and processing are challenging, and so far all protein structures determined using FEL data were phased by molecular replacement. Experiments at the SACLA FEL in Japan show that the quality of SFX data can be high enough to detect the weak anomalous signal of endogenous sulfur in a protein, opening the way to de novo phasing from FEL data.