Extended Data Fig. 8. The full length PorLM volume is compatible with the shape of GldLM′ but not with the domain arrangements of earlier crystallographic structures of GldM (6ey4,) or PorM (6ey5) fragments.

The PorLM volume is contoured at 2.5s and the upper and lower panels are related by a 90° rotation about the y axis. The approximate domain boundaries are indicated by the dashed lines and domains in these regions are labelled on the right hand side of the figure.

The cryoEM structure of GldLM′ is positioned by docking the GldM′ TMHs onto the PorM TMHs as described in the text and Fig. 3.

The D1 dimer of GldM 6ey4¹⁵ is docked into the D1 portion of the volume and shows (1) poor fit within D1 because the centre of the closed crystallographic dimer protrudes from the volume and (2) poor fit in the D2-D4 region when no bend is introduced between D1-D2.

PorM 6ey5¹⁵ is positioned by placement of D2 into its portion of the volume and shows a poor fit for D3-4 which protrude from the volume.

The hybrid model presented in Figure 3 is shown for comparison, with GldM coloured as in other panels and GldL chains coloured individually.