Synchrotron SAXS data from NS-Tir in 100 mM Tris-HCl, 150 mM NaCl, 1 mM EDTA, 1 mM DTT, pH 8.0 were collected on the B21 beam-line at the Diamond Light Source (Didcot, UK) using a Pilatus 2M detector at a sample-detector distance of 2.696 m and at a wavelength of λ = 0.0946 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). In-line size-exclusion chromatography (SEC) SAS was employed using an Agilent 1200 HPLC System by injecting a 60 μl sample at 25 mg/ml under a flow rate of 0.16 ml/min onto Shodex KW402.5-4F column (Showa Denko F.F.) at 10°C collecting 915 successive 2-second frames. The scattering intensities from NS-Tir elution peak region (35-frames) were integrated, buffer subtracted and averaged using the ScÅtter software to produce the averaged SEC-SAXS profile. From this profile, the pair-wise distance distribution function, P(r), was obtained by indirect Fourier Transform with GNOM using a momentum transfer range of 0.09 < s <3.59 nm-1. The Rg values were estimated by applying the Guinier approximation in the range s < 1.3/Rg. The displayed SAXS-generated ab initio molecular reconstruction was obtained using GASBOR.
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