Extended Data Figure 7: Comparison of the SAXS, EM and X-ray structures of TssA.
From: Priming and polymerization of a bacterial contractile tail structure
a, Schematic representation and colour code of the constructs used for SAXS (grey), electron microscopy (light blue) and X-ray (TssANt, dark blue; TssACt, red) analyses. The epitopes and theoretical molecular masses of the domains are indicated. TRX, thioredoxine; N, N terminus; C, C terminus. b, Fit between the experimental data (green dots) and the calculated scattering curves for TssANt2 and TssACt generated by CRYSOL (red line). c–f, SAXS/X-ray comparison. Top (c), side (d) and bottom (f) views of the fitting of TssANt2 (blue ribbon) and TssACt (red ribbon) X-ray structures into the TssA SAXS envelope (transparent grey surface). Scale bars are 10 nm. e, Magnification of a cut-away section of the fitting shown in d. Scale bar is 5 nm. g–i, SAXS/EM/X-ray comparison. Top (g) and side (h) views of the superimposition of SAXS (grey surface), EM (transparent light-blue surface) and X-ray structures of TssA. Scale bars are 10 nm. i, Magnification of a cut-away section of the superimposition shown in h. j–n, EM/X-ray comparison. Top (j), side (k) and bottom (l) views of the fitting of TssANt2 (blue ribbon) and TssACt (red ribbon) X-ray structures into the TssA EM envelope (transparent grey surface). Scale bars are 10 nm. m, n, Magnifications of the top and bottom views of the docking of the TssA domain X-ray structures into the TssA EM map highlighting the interface between the TssA central core (TssACt, red ribbon) and arms (TssANt2, blue ribbon). The C-terminal helix of TssANt2 (ends at position 377) and N-terminal helix of TssACt (starts at position 395) are shown in yellow. o, Top view of the fitting of the X-ray structure of EAEC Hcp (green ribbon, PDB 4HKH56) into the TssA SAXS envelope (grey surface). The scale bar is 10 nm.
