Fig. 4: DmxA DGC activity is switched on upon recruitment to the division site.

a Analysis of cdGreen2 and mScarlet-I fluorescence in the indicated strains. Upper panels, epifluorescence snapshot images of representative cells expressing cdGreen2 and mScarlet-I. White arrowheads indicate cells with high cdGreen2 fluorescence. The cdGreen2-mScarlet-I operon was expressed from the constitutively active pilA promoter. Scale bar, 5 μm. Lower panels, scatter plots of the cdGreen2/mScarlet-I fluorescence ratio of each cell relative to its cell length. Colors indicate the density of points according to the scale on the right. Total number of cells from one biological replicate indicated. b, c cdGreen2 fluorescence in representative Δ10 (b) and ΔdmxA (c) cells during the cell cycle. Upper panel, epifluorescence and phase-contrast images from time-lapse microscopy of representative cells. Images were recorded every 10 min; arrowheads indicate completion of cytokinesis (defined as the first frame in which daughters were clearly separated). In (b), lower panels, histograms of the timing of appearance of the cdGreen2 fluorescence signal relative to completion of cytokinesis and lifetime of the high cdGreen2 fluorescence signal (n = 130 division events from three biological replicates, number of events per replicate in brackets). Error bars, mean ± SD. The first time point after completion of cytokinesis is defined as t = 0 and indicated by a gray vertical bar. In (c), n = 67 division events from three biological replicates, number of events per replicate in brackets. d FRAP experiment on predivisional Δ10 cells expressing cdGreen2 and mScarlet-I. The mScarlet-I signal of one half of a cell was bleached in the region indicated by a white circle. Post-bleached images were recorded 2 s after the bleaching event. All predivisional cells analysed had a high cdGreen2 fluorescent signal. n = 22 from one biological replicate. Scale bar, 2 μm. Source data are provided as a Source Data file.