Extended Data Fig. 8. Characterization of the FtsZ(K86E) suppressor mutant.

a Each pair of images shows cell morphology (phase-contrast imaging, left), and Z ring morphology (epifluorescence images of cells expressing FtsZ-mNeonGreen induced with 20 μM IPTG for 2 hours, right) in FtsZ(K86E) and FtsZ(K86E) ΔezrA ΔzapA cells. FtsZ(K86E) Z rings look similar to the control. Z rings in FtsZ(K86E) ΔezrA ΔzapA are somewhat perturbed, but less so than typical cells missing synthetically lethal combinations of ZBPs; they also have polar Z rings, as is typical for ΔezrA strains. Representative images from at least two replicates of each condition. Scale bars: 2 μm. b FtsZ(K86E) and FtsZ(K86E) ΔezrA ΔzapA have similar FtsZ treadmilling velocities to control (left), and FtsZ(K86E) Z rings are identical in width to control, while FtsZ(K86E) ΔezrA ΔzapA are wider (right). For velocity measurements in each strain, FtsZ-mNeonGreen was induced with 20 μM IPTG for 2 hours, imaged by TIRFM, and analysed from kymographs. For Z ring width measurements, FtsZ-mNeonGreen was induced with 20 μM IPTG for 2 hours and imaged by epifluorescence. c Pbp2B intensity at midcell in FtsZ(K86E) mutant cells. Left: Representative images of Pbp2B in the indicated strains, visualized by epifluorescence imaging of cells expressing Pbp2B-mNeonGreen, from at least 4 replicates of each condition. Right: Pbp2B intensity at the division site in each strain. Although the FtsZ(K86E) restores viability in a ΔezrA ΔzapA strain, it does so without rescuing Pbp2B recruitment to midcell. For each box plot, the white line indicates the median, the box extends to the 25^th and 75^th percentiles, and the whiskers indicate 1.5x interquartile range. P-values were obtained from a two-sided t-test; ns indicates p > 0.5, **** indicates p<0.0001, and p-values are included in parenthesis. N>5000 division sites for each condition. Scale bars: 2 μm.