FIG 3 .
Conserved cell division protein FtsQ is required for localization of IcsA to the pole. (a) Hierarchical recruitment of cell division proteins (33). (b) Position of IcsA507-620-GFP in E. coli MG1655 or an MG1655 crp rssB mutant, carrying vector, p-ddlB-ftsQ, p-ddlB, or p-ftsQ, grown to stationary or exponential phase. (c) Distribution of native IcsA on the surface of intact cells of WT S. flexneri 2457T or an ftsQ1(Ts) derivative visualized by immunofluorescence (IF). Growth was at 37°C, the restrictive temperature for ftsQ1(Ts) cells, for 1 h. Aztreonam was used to filament WT (WT + aztr) and complemented ftsQ1(Ts) cells during the 1-h period; addition of aztreonam per se had no effect on distribution of IcsA. (d) Rescue of cell division upon shift of S. flexneri 2457T ftsQ1(Ts) to 30°C following 2 h of growth at 37°C. Bars, 10 µm.