Figure 5. Solution structure of EspG_5mtu.

(a) Experimental SAXS data (black circles) and computed fits (solid lines) with respective discrepancy values (χ²). The theoretical SAXS curve of the EspG_5mtu crystal structure when in complex with PE25/PPE41 as calculated using CRYSOL (purple) (PDB ID 4KXR, chain C) fits the experimental SAXS data with a χ² of 1.2 and an apparent misfit around s = 1.8 – 2.0 nm^-1. To calculate the EOM fit, the 24 amino acid residues that were missing from the crystallographic structure of EspG_5mtu were added at the N-terminus and flexibility of all loops was allowed. This procedure resulted in an improvement of the fit to a χ² value of 0.99 (blue). (b) The amino acid residue root-mean- square-fluctuation (RMSF) of EspG_5mtu (starting structure PDB ID 4KXR, chain C) during a molecular dynamics simulation run. The secondary structure assignment of the crystallographic structure is shown above the RMSF plot for reference, where β-sheets and α-helices are represented by arrows and rectangles, respectively. (c) The flexible loop regions and the amino acid residues missing from the crystallographic structure of EspG_5mtu crystal structure when in complex with PE25-PPE41 (purple) are modeled as dummy residues (blue spheres).