Figure 3.

Small-angle X-ray scattering data for PmScsCΔN. (a) Measured scattering data for PmScsCΔN. The scattering profile of a rigid-body model is shown as a solid black line overlaid on the scattering data for PmScsCΔN [χ² = 1.12; CorMap test (Franke et al., 2015 ▸), 302 points, C = 14, P = 0.018]. Inset: Guinier plot for PmScsCΔN (R ² = 0.991). (b) The pair-distance distribution function, p(r), derived from the scattering data is indicative of a globular structure for PmScsCΔN (multiplied by a factor of four for clarity) with a maximum dimension of ∼55 Å. (c) Probable shape of PmScsCΔN obtained from the filtered average of 16 dummy-atom models (green envelope): χ² = 1.079 ± 0.001; NSD = 0.522 ± 0.007; resolution = 19 ± 2 Å. The image in (c) was generated using PyMOL, where the grey shape represents the total volume encompassed by the aligned dummy-atom models and the crystal structure is shown as a ribbon diagram aligned with the filtered model (dark green).