FIG 4.

E. coli Dps induces the formation of the stationary-phase-specific biocrystal. Shown is the E. coli nucleoid structure bounded within cell membranes, where brown circles represent ribosomes, yellow shapes represent DNA, and blue circles represent Dps dodecamers. (A) During log phase, chromatin is interspersed with the translation machinery. (B) During the transition between log phase and stationary phase, toroids composed of regularly spaced Dps-DNA nucleoprotein complexes form, which are segregated from ribosomes. (C) By late stationary phase, the nucleoid has been restructured to a regularly spaced “biocrystal” nucleoprotein complex, which is segregated from ribosomes. Double helices in panel C represent locally parallel DNA within the crystalline nucleoid. The image is not to scale. (Model inspired by Frenkiel-Krispin and colleagues [24, 25]; created with BioRender.com.)