Synchrotron SAXS data from solutions of ATP-dependent RNA helicase DDX3X (1-580) in 20 mM Tris, 150 mM NaCl, 10% (v/v) glycerol, 1 mM TCEP, pH 8 were collected on the SAXS/WAXS beam line at the Australian Synchrotron (Melbourne, Australia) using a Pilatus 1M detector at a sample-detector distance of 1.4 m and at a wavelength of λ = 0.103 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 50.00 μl sample at 10 mg/ml was injected at a 0.30 ml/min flow rate onto a GE Superdex 200 5/150 column at 16°C. 33 successive 1 second frames were collected through the sample SEC elution peak. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent-blank was subtracted.