FIGURE 1. Density maps of the flagellar filament with the atomic model of full-length flagellin superimposed.

a, The whole molecule, prepared with O⁴¹. Domains D0, D1, D2, D3 and the spoke region are labelled D0, D1, D2, D3 and S, respectively. b, Magnified stereo view of the terminal chains in domain D0. The magnified area is indicated by a box in a. The atomic model of a subunit at the centre is drawn in stick representation and atoms are coloured as: carbon, yellow; nitrogen, blue; oxygen, red. The other subunits surrounding it are drawn in thin wire representation and are coloured pink. The figure was prepared with XTALVIEW⁴⁵ and RASTER3D⁴⁶. Contour levels of the maps are about 2.