Synchrotron SAXS data from solutions of HisBP with a 5-fold excess of histidine in 100 mM NaCl, 20 mM NaPO4, 0.5 mM TCEP, pH 7.4 were collected on the BM29 beam line at the ESRF (Grenoble, France) using a Pilatus 1M detector at a sample-detector distance of 2.8 m and at a wavelength of λ = 0.09919 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). One solute concentration of 4.20 mg/ml was measured at 20°C. 12 successive 2 second frames were collected. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent-blank was subtracted.
His-bound HisBP at a ligand:protein ratio of 5:1. Ligand condition is prepared by dissolving histidine in powder form (Sigma-Aldrich) directly into the SAXS buffer, followed by dilution to the target concentration with additional SAXS buffer.
s, nm-1
