Fig. 4: Careless accurately merges time-resolved polychromatic diffraction data.
From: A unifying Bayesian framework for merging X-ray diffraction data
a When exposed to blue light, the PYP chromophore undergoes trans-to-cis isomerization. In total, 40 images from a single crystal of PYP were processed: 20 were recorded in the dark state, and 20 were recorded 2 ms after illumination with a blue laser pulse. Each image is the result of 6 accumulated X-ray pulses. The signal to noise and multiplicity of each time point is reported in Supplemental Fig. 4. b The data were randomly divided in half by image and merged with scale function parameters learned by merging the full data set. Merging with Careless gave excellent correlation between the structure factor estimates of both halves. Error bars indicate the standard deviation of the structure factor posteriors for the half data sets around the posterior means. c Half-dataset correlation coefficients as a function of resolution, including both the dark and 2 ms data. d Ground-state 2Fo − Fc map created by refining the ground-state model (PDBID: 2PHY) against the dark merging results (countoured at 1.5 σ). The phases of this refined model were used for the difference maps in (e-g). e F2ms − Fdark time-resolved difference map showing the accumulation of blue positive density around the excited state chromophore (blue model, PDBID: 3UME) and depletion of the ground state (yellow model, PDBID: 2PHY). f F2ms − Fdark weighted time-resolved difference map showing localization of the difference density to the region surrounding the chromophore. g F2ms − Fdark weighted time-resolved difference map showing large differences around the chromophore. All difference maps are contoured at ± 3.0σ.
