Fig 3.

Discovery of metabolic enzyme CtpS as a novel filament-forming protein in Caulobacter crescentus. (A) A time-lapse series of images of the GFP-labeled crescentin structure (red; laid over phase-contrast images) during the course of the cell cycle shows crescentin localizing to the short axis of curved C. crescentus cells. (B and C) Cryo-ET confirmed the presence of filament bundles (B), though bundles were still present in a crescentin deletion strain (C). This led to the discovery of metabolic enzyme CtpS as a novel filament-forming protein in C. crescentus. (D) CtpS and CreS colocalize. Bars, 1 μm (A), 200 nm (B), 50 nm (C), and 2 μm (D). Structural features in panel B: SL, surface layer; OM, outer membrane; PG, peptidoglycan layer; IM, inner membrane; St, stalk; Rib, probable ribosome; GF, gold fiducial used to align images; Phb, putative poly-β-hydroxybutyrate granule. Panel A adapted from reference 133 with permission from Cold Spring Harbor Laboratory Press; panel B adapted from reference 52 with permission from John Wiley and Sons; panels C and D adapted from reference 134 with permission from the Nature Publishing Group.