Synchrotron SAXS data from solutions of ATP-dependent Clp protease ATP-binding subunit ClpC1 (second state) in 50 mM HEPES, pH 7.5, 100 mM KCl, 10% v/v glycerol, 4 mM MgCl2 and 1 mM ATP were collected on the BM29 beam line at the ESRF storage ring (Grenoble, France) using a Pilatus 1M detector at a sample-detector distance of 2.9 m and at a wavelength of λ = 0.099 nm (l(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). Size-exclusion chromatography SEC-SAXS was performed on a sample at at 20°C. 50 successive 1 second frames were collected through the corresponding SEC elution peak. Each data frame was normalized to the intensity of the transmitted beam and radially averaged (2D- to 1D data reduction). The scattering of the solvent-blank (reduced data obtained from the elution buffer) was subtracted from each sample frame and the resulting subtracted SAXS profiles were scaled and averaged to generate the data displayed in this entry.