Dissecting the role of conformational change and membrane binding by the bacterial cell division regulator MinE in the stimulation of MinD ATPase activity.

The bacterial cell division regulators MinD and MinE together with the division inhibitor MinC localize to the membrane in concentrated zones undergoing coordinated pole-to-pole oscillation to help ensure that the cytokinetic division septum forms only at the mid-cell position. This dynamic localization is driven by MinD-catalyzed ATP hydrolysis, stimulated by interactions with MinE's anti-MinCD domain. This domain is buried in the 6-β-stranded MinE "closed" structure, but is liberated for interactions with MinD, giving rise to a 4-β-stranded "open" structure through an unknown mechanism.

Appropriation of the MinD protein-interaction motif by the dimeric interface of the bacterial cell division regulator MinE.

MinE is required for the dynamic oscillation of Min proteins that restricts formation of the cytokinetic septum to the midpoint of the cell in gram negative bacteria. Critical for this oscillation is MinD-binding by MinE to stimulate MinD ATP hydrolysis, a function that had been assigned to the first ∼30 residues in MinE. Previous models based on the structure of an autonomously folded dimeric C-terminal fragment suggested that the N-terminal domain is freely accessible for interactions with MinD.