Fig. 6.

Fitting of the FlhA^C ternary complexes into the cryoEM density map of the flagellum base body⁴⁴. The nonameric oligomeric structure of FlhA^C was generated using the structure of the homologous MxiA protein²⁸. The ternary structures obtained in this work were then used to model the complete oligomeric nonameric ring of FlhA^C bound to nine molecules of a FliT−FliD and b FliS−FliC. Non-cooperative binding of the chaperone–substrate molecules on FlhA^C is assumed. The full-length FliD (5H5V) and FliC (PDB ID 3A5X) structures were used. FliI is the hexameric flagellar ATPase. CM cytoplasmic membrane; OM outer membrane. Side views of half-cut sections and bottom views are shown. The colors of the FlhA^C-chaperone–substrate complexes are as in Figs. 2 and 3