Figure 8
From: Rotational direction of flagellar motor from the conformation of FliG middle domain in marine Vibrio
The C ring model of the effects of the mutations in FliG. (A) The model of C ring in Vibrio alginolyticus. Dashed flames of left and right enlarge 1 set of the C ring (containing one molecule of CheY, FliM, FliG, and FliF) and 3 sets, respectively. (B) The mutations in FliG were mapped on 1 set of their components as described in (A). Blue, red, and black balls indicate counterclockwise (CCW)-biased rotation, CW-biased rotation, and tumble phenotype, respectively. FliGC interacts with the stator. (C) The model of the determination of the rotational direction in the C ring. Black arrows show how CheY binding to FliM affects the EHPQR motif in FliGM. Blue arrows show the conformational change in intramolecular FliG. Dashed blue arrows show the effect of the conformational change of FliG on the intermolecular FliG. In our model, CheY binding to FliM induces the conformational change in FliGM. This change is sensed by Gly-Gly flexible linker causing the steric hindrance of the conformation of FliGC. The conformational change of FliGC affects FliG at both side of ring, being transmitted to the whole FliG of the C ring. Interaction surface between FliGC and the stator slides, so that the rotational switching occurs. FliG in the E144D, Q147H, P188L, and A218V mutants affects FliG at both sides. In contrast, FliG in the G214S and G215A mutants causes the steric hindrance of FliGC.
