Synchrotron SAXS data from solutions of WT flLRH-1 / CYP7A1 oligo duplex / PGC1 alpha co-activator peptide in 20 mM TRIS, 150 mM NaCl, 2% v/v glycerol, 0.5 mM CHAPS, 5 mM DTT, pH 7.5 were collected on the SIBYLS 12.3.1 beam line at the Advanced Light Source (ALS; Berkeley, CA, USA) using a Pilatus3 X 2M detector at a sample-detector distance of 2.1 m and at a wavelength of λ = 0.1127 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 100.00 μl sample at 7.5 mg/ml was injected at a 0.45 ml/min flow rate onto a Shodex KW-800 series column at 20°C. 500 successive 3 second frames were collected continuously during the ~25 minute elution. After 2D-to-1D radial averaging, the data were analyzed through the SEC elution peak of the sample (from which I(0) and Rg were evaluated using the Guinier approximation) and the scattering of an appropriate solvent-blank was subtracted.