Figure 2
Analysis of HD-PTP by Small Angle X-ray Scattering. (A–C) Plots of X-ray scattering intensity log(I(q)) as a function of the scattering vector q (Å−1) for HD-PTPCC (A), HD-PTPBro1-CC (B) and HD-PTPBro1-CC-PRR (C). SAXS data are shown as grey open circles and the normalised fit from the best individual molecular model is shown as a red line (calculated with FoXS55, goodness of fit indicated with its χ2 value). Ab initio reconstructions calculated with DAMAVER52 are shown as transparent envelopes with the best individual models superimposed using the automatic map fitting tool in Chimera58. The N-terminal tails of HD-PTPBro1-CC and HD-PTPBro1-CC-PRR are not shown, for clarity. (D) Variation of the goodness of fit (χ) with the HD-PTPCC SAXS data as a function of the distance between the centre of mass of subdomains CC1 and CC2 (dCC1-CC2). Fits from crystal structure coordinates of HD-PTPCC (blue) and AlixV (grey, closed forms; green, open forms) are individually shown (selected PDB ID codes indicated). Fits from HD-PTPCC models with varying CC1-CC2 distances are shown as red triangles. Filled triangles correspond to models with calculated sedimentation coefficients (SOMO45) consistent with the experimentally observed value (Table 1). Best χ values and agreement with hydrodynamic data are observed for the extended forms.
