Synchrotron SAXS data from solutions of the GAP domain of Vibrio cholerae Outer Protein E (VopE) in 10 mM HEPES-HCl, pH 7.4, 150 mM NaCl, 0.5 mM TCEP, were collected on the BioCAT 18ID beam line at the Advanced Photon Source (APS), Argonne National Laboratory (Lemont, IL, USA) using a Pilatus3 X 1M detector at a sample-detector distance of 1.5 m and at a wavelength of λ = 0.1033 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). In-line size-exclusion chromatography (SEC) SAS was employed. The SEC parameters were as follows: A 300 μl sample at 19.5 mg/ml was injected at a 0.75 ml/min flow rate onto a GE Superdex 75 Increase 10/300 column at 25°C. 1254 successive 1 second frames were collected through the entire SEC elution. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of an appropriate solvent-blank was subtracted from data acquired through the SEC elution peak of the sample.