Fig. 4: The flexible D2 domain is dispensable for S-layer assembly.
a Cartoon representation of the SlpARΔD2 H/L complex crystal structure (slate blue and gold, PDB ID: 7ACZ), superimposed onto SlpACD630 H/L complex structure (PDB ID: 7ACY, grey). Deleted D2 region is marked with a dashed line on the CD630 structure and corresponding schematic representation of the complex. Views as in Fig. 1b. 2D schematic of H/L complex crystal packing in SlpARΔD2, indicating the interaction network linking a single H/L (slate blue/gold) complex with five other molecules in a planar arrangement generated by SLPH tiling. b Superimposition of the 3D reconstruction of negatively stained S-layer ghost containing SlpA devoid of domain D2 (SlpARΔD2, light blue solid surface) on the reconstruction of native wild-type S-layer ghost (SlpAR20291, grey mesh). The missing density can be largely ascribed to that of the missing D2 domain (indicated with black arrowheads). Views as in Fig. 2d. c Fit of the SlpARΔD2 structure determined by X-ray crystallography (coloured as in c) into the S-layer (grey) reconstruction indicates a similar arrangement in the crystal packing and the native array. Views as in b.
