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Figure 1
Alternative models of correlated displacements in a liquid-like motions model, compared by Peck et al. (2018BB14). Each panel depicts a 2 × 3 unit-cell section extracted from the (010)–(001) layer of crystalline cyclophilin A [PDB entry 2cpl (Ke, 1992BB7), used in Peck et al. (2018BB14)]. The b axis is aligned with the vertical direction, and the c axis with the horizontal. Each P212121 unit cell contains four copies of the protein that arrange into a sawtooth in this projection. The strength of correlation with an atom near the center (Asp26 Cα, highlighted as a red sphere) is indicated using a heat map. The correlation decays exponentially with distance, according to a liquid-like motions model (Caspar et al., 1988BB3). (a) The original model, in which correlations extend to atoms on different proteins. (b) A modified model, in which correlations are limited to atoms on the same protein. Peck and coworkers (Peck et al., 2018BB14) found that diffuse scattering data for this and two other systems favor model (a) over model (b). The figure was created using PyMol (https://sourceforge.net/projects/pymol/).

IUCrJ
Volume 5| Part 2| March 2018| Pages 120-121
ISSN: 2052-2525
https://doi.org/10.1107/S2052252518002713