TmMreB Assembles into Double Filaments and Sheets on a Lipid Membrane Surface
(A) Negative-stain electron micrograph of untagged, wild-type TmMreB (pFE349) filaments assembled on a lipid monolayer in the presence of AMP-PNP. Scale bar, 50 nm.
(B) Digital section through a 3D cryo-electron tomography reconstruction of TmMreB filaments assembled on lipid vesicles in the presence of AMP-PNP. Here the membrane is composed of a bilayer rather than a monolayer. Scale bar, 50 nm.
(C) (Left) Single particle reconstruction of the TmMreB double filament based on negative stain images similar to that shown in (A). Scale bar, 5 nm. The crystal structure of TmMreB protofilaments is shown to scale (middle) and docked into the single particle reconstruction (right).
(D) Model for the interaction of an MreB filament with the membrane. The membrane insertion loop required for TmMreB is shown, as well as the N-terminal amphipathic helix from EcMreB.