FIG. 4.

Intracellular cytoskeletal structures formed by the actin-like MamK protein (A and B) and the intermediate filament homolog crescentin (C). (A and B) Electron cryotomography (A) and cartoon illustration (B) of magnetosomes located under the surface of the cytoplasmic membrane of Magnetospirillum magneticum. MamK filaments extend along the surface of the linear array of membrane-bounded magnetosome structures (white arrows in panel A). (The electron micrograph was reprinted from reference 101 with permission of AAAS.) (C) The intermediate filament-like protein crescentin (green), visualized by expressing GFP-tagged crescentin in wild-type cells, forms filamentous structures (white arrows) along the concave edge of C. crescentus. Membranes (in red) are stained with dye FM 4-64. (Reprinted from reference 8 with permission from Elsevier.)