Supplementary Figure 7: Symmetry mismatch.
From: Domain-swap polymerization drives the self-assembly of the bacterial flagellar motor
The FliF template exists as a 26-fold symmetry ring, while the C-ring, consisting of FliG, FliM and FliN, exists as a 45 nm 34-fold symmetric ring. Thus there exists a mismatch in the symmetry between the two rings. This could manifest itself as gaps in the FliG ring (A, left), but our model predicts that there is a strong thermodynamic drive to fill these gaps (A, right). If these gaps are indeed plugged by FliG, then in the functional FliFG fusion construct there could be 8 dangling FliF subunits that are not incorporated into the MS-ring template, but are fused to the FliG molecules that are plugging gaps in the C-ring (B).
