[Frontiers in Bioscience S5, 564-574, January 1, 2013]

The mechanics of shape in prokaryotes

Siyuan Wang1,3, Joshua W. Shaevitz2,3

1Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA 2Department of Physics, Princeton University, Princeton, NJ 08544, USA 3Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA

FIGURES

Figure 1. Bacterial cell wall structure. (A) Cell wall subunit. (B) Cross-link between glycan strands.

Figure 2. Models of bacterial cell wall architecture. (A) Single-layered planar model and scaffold model of E. coli cell wall. (B) Multiple-layered model and cable model of B. subtilis cell wall. The cartoons are only schematic. For the multiple-layered model, the number of layers is not exact. For the cable model, the number of glycan coils in each cable and the pitch of coils are not exact.

Figure 3. The biochemical pathway of the cell-wall precursor synthesis.

Figure 4. Localization, dynamics, and function of bacterial cytoskeleton. (A) Fragmented MreB filaments (magenta) move in a near-circumferential direction, powered by peptidoglycan synthesis (blue arrows). (B) FtsZ ring (red) localizing at the mid-cell consists of short protofilaments. A small constriction force from the Z-ring (black arrows) may bias the cell-wall growth inward. (C) CreS (green) filament may reduce the turgor-pressure induced strain (black arrows; thickness indicates magnitude) on one side of the cell wall, leading to less wall synthesis on that side.