Extended Data Figure 7: The Z ring protein EzrA shows impaired treadmilling in the presence of PC190723 and biphasic ring constriction.
From: Peptidoglycan synthesis drives an FtsZ-treadmilling-independent step of cytokinesis
a, ColpSGEzrA-GFP cells that express a functional EzrA fusion to GFP were imaged by SIM every 5 s in the absence (EzrA control) or presence (EzrA + PC) of PC190723. Kymographs were obtained by extracting fluorescence intensity values along the red line indicated in cells in the left panels. Similar to the observations for FtsZ55–56sGFP, the addition of PC190723 abolished EzrA movement (vertical lines in the kymographs). b, ColpSGEzrA-GFP cells were imaged by SIM every 5 min in the absence (left) or presence (right) of PC190723, and kymographs that show the constriction of EzrA–GFP rings were plotted. Under control conditions, the larger EzrA rings showed biphasic constriction behaviour whereas in the presence of PC190723 only rings in the second stage of cytokinesis were able to constrict. Data in a and b are representative of two biological replicates. Scale bars, 1 μm. c, To test the functionality of the EzrA–GFP construct, the strains COL, ColpSGEzrA-GFP and COLΔEzrA (which lacks ezrA) were imaged by phase contrast and cell areas were measured. The lack of EzrA in COLΔEzrA (n = 959) resulted in cell enlargement, whereas the size distribution of ColpSGEzrA-GFP (n = 957) cells mimicked that of parental strain COL (n = 851), which indicates that the EzrA fluorescent fusion is functional.
