Fig. 5
From: MglA functions as a three-state GTPase to control movement reversals of Myxococcus xanthus
Model of the three-state MglA switch. 1 The MglA-GTP cluster located at the front pole of the gliding bacteria is composed of a major species stably associated to the pole which is resistant to MglB (MglA-GTP*, T* in kaki) and a minor diffusible species (MglA-GTP, T, in green) that can reach the lagging pole to be inactivated into MglA-GDP (D in mauve) by MglB (B, in orange). 2 During a reversal event, MglA-GDP is released in the cytosol to reach the leading pole where it converts all polar MglA-GTP* into diffusible MglA-GTP, which detaches rapidly from the pole. 3 MglA-GTP is rapidly inactivated into MglA-GDP by MglB at the lagging pole. 4 MglA-GDP is reloaded with GTP by a GEF activity to regenerate MglB-resistant MglA-GTP*, and MglB relocates to the opposite pole. 5 A new leading pole is established, resuming movement in the opposite direction. The direction of movement at steps 1 and 5 is shown by a black arrow, the reversal event spanning steps 2−3−4 is indicated by a vertical line.
