view article
Figure 4
Comparison results of the phase retrieval using prior initial phases and random initial phases. Tests were conducted using the protein 6zfp. (a) Evolution of the electron-density maps at different iterations during the phase retrieval process. In the upper row, the initial map is calculated with phases of the predicted model. In the lower row, the initial map is calculated with random phases. The real protein structure is well docked into each recovered electron-density map. (b) FSC curve calculated by recover density and real density maps. The magenta and blue lines represent the recover density from the random initial phases and prior initial phases, respectively. The yellow line represents an average density of five recover densities from five independent random phases. The dotted line indicates the resolution of the reconstructed 3D electron-density map, where FSC drops to 0.5. (c) Half FSC curve. The dataset was randomly split into two sets of equal size. Orientation determination and phase retrieval were performed independently on each set. An FSC was then calculated based on the two resulting density maps. The magenta and blue lines represent recover density from random initial phases and prior initial phases, respectively. Note that the commonly used threshold in half FSC is 1.4. (d) Phase-retrieval transfer function from five successful recovered density maps from different random initial phases. The resolution is estimated by applying a threshold to the PRTF at e−1.

IUCrJ
Volume 11| Part 4| July 2024| Pages 602-619
ISSN: 2052-2525
https://doi.org/10.1107/S2052252524004858