Fig. 5

Conceptual diagrams. a Peptidoglycan from rod-shaped E. coli (MG1655) is not crystalline yet has quantifiable orientational order with chains likely to be in a circumferential direction. This corresponds to the direction of maximum stress in the cylindrical part of the cell (stress is isotropic at the poles). It contains glycans up to 200 nm long. b Peptidoglycan from roughly spherical E. coli (lacking MreB or treated with A22) is much less ordered and has shorter glycan chains. Stress is isotropic in this case