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Synchrotron SAXS data of the P. berghei multi-aminoacyl-tRNA synthetase Q complex containing the N-terminal GST-like domains of tRNA import protein (tRip-N), glutamyl-tRNA synthetase (ERS-N) and glutaminyl-tRNA synthetase (QRS-N). The experiment was performed on the SWING beamline at the SOLEIL synchrotron (Saint-Aubin, France) using an EigerX 4M at a sample-detector distance of 2 m and at a wavelength of λ = 0.1033 nm. In-line size-exclusion chromatography was used to separate the sample prior to X-ray exposure. 50 μl of purified recombinant (E. coli) complex at 11 mg/mL were injected on a Bio SEC-3 column (4.6 × 300 mm, 300 Å) equilibrated in 25 mM HEPES-NaOH pH 7.0, 300 mM NaCl, 5% glycerol, 0.005% (m/v) DDM, 5 mM 2-mercaptoethanol at 0.2 mL/min and 15°C. Frames (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle) were collected succesively each 1 s (0.990 s exposure and 0.01 dead time) in two time windows. 180 solvent frames were collected at time 2.5 min prior to the column's void volume and 1230 sample frames were collected from time 9.5 min until the end of the run. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent was subtracted from the sample frames using Foxtrot 3.5.10. Correction for capillary fouling was applied using the US-SOMO 4.0 HPLC SAXS module. Data analysis was performed with BioXTAS RAW 2.1.0. The experimental molecular weight was determined using the method of the volume of correlation. A correction factor has been applied to the Porod volume. The atomic model of tRip-N was built with MODELLER 10.1 based on the crystal structure of P. vivax tRip-N (PDB 5ZKF). The crystal structure of ERS-N is available (PDB 8BCQ). QRS-N is a prediction model obtained with Raptor X. The interaction interfaces of the different subunits has been validated by mutagenesis and pull-down experiments. The interaction between tRip-N and ERS-N occurs through a GST-like interface 2 and was modeled based on similar homodimeric assemblies observed in the crystal structures of P. vivax tRip-N (PDB 5ZKF) and P. berghei ERS-N (PDB 8BCQ). The interaction between ERS-N and QRS-N likely occurs through a canonical GST-like interface 1 and was modeled based on the dimer of ERS-N (PDB 8BCQ). The model of the Q complex dimerizing through an alternative GST-like interface 1 of tRip-N fits well the SAXS data.
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s, nm-1
