General resistance of isolated ftsZ alleles to assembly inhibition.

<p>(A) Cells with <i>ftsZ_V208A</i> or <i>ftsZ_L169R</i> form FtsZ rings and do not filament despite overexpression of <i>minCD</i>. Representative IFM micrographs are shown of cell wall (red) and α-FtsZ (green) signal from fixed cells of the CC4506 background strain with pDSW210-<i>his</i>-<i>minCD</i> (<i>minC-minD</i> gene fusion) and the indicated <i>ftsZ</i> alleles grown at 30°C (no <i>kil</i> induction) harvested after 40 minutes of <i>minCD</i> induction (+IPTG) or non-inducing conditions. Cell wall and α-FtsZ signal are shown as in <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004217#pgen-1004217-g002" target="_blank">Figure 2</a>. Scale bar = 5 µm. (B) Cells with <i>ftsZ_V208A</i> or <i>ftsZ_L169R</i> form FtsZ rings and do not filament despite <i>sulA</i> overexpression. Shown are representative IFM micrographs of cell wall (red) or α-FtsZ (green) signal from fixed cells of the CC4506 background strain with pBAD33-<i>sulA</i> and the indicated <i>ftsZ</i> alleles grown at 30°C (no <i>kil</i> induction) harvested after 40 minutes of <i>sulA</i> induction (+Ara) or non-inducing conditions. Signal and scale are as in (A). (C) The <i>ftsZ</i> mutations confer resistance to <i>minCD</i>- or <i>sulA</i>-induced lethality. Spot dilutions are shown of the CC4506 background strain with pDSW210-<i>his</i>-<i>minCD</i> or pBAD33-<i>sulA</i> and the indicated <i>ftsZ</i> alleles plated at 30°C (no <i>kil</i> expression) on LB agar with 1 mM IPTG (+IPTG) or 0.2% arabinose (+Ara). (D) Cells with the characterized <i>ftsZ9</i> and <i>ftsZ114</i> alleles partially suppress inhibition of FtsZ ring formation by Kil. Shown are representative IFM micrographs of cell wall (red) or α-FtsZ (green) signal from fixed cells containing the indicated <i>ftsZ</i> allele and pBAD33-<i>kil</i> grown after 40 minutes of <i>kil</i> induction (+Ara). Signal and scale as in (A). (E) Cells with the <i>ftsZ9</i> allele completely suppress, and those with the <i>ftsZ114</i> allele partially suppress the loss of viability upon <i>kil</i> expression. Shown are spot dilutions of cells containing the indicated <i>ftsZ</i> allele and pBAD33-<i>kil</i> plated on LB agar with (right) or without (left) 0.2% arabinose at the indicated dilutions.