Nutrient-mediated growth rate regulation of DNA replication initiation is independent of Soj, YabA, and (p)ppGpp.

<p>(<b>A</b>) Growth rate regulation of DNA replication initiation is maintained in either Δ<i>soj</i> or Δ<i>yabA</i> mutants. Strains were grown overnight at 37°C in minimal media supplemented with succinate and amino acids (20 µg/ml). The culture was diluted 1∶100 into various media (succinate, glycerol, glycerol + amino acids, LB) to generate a range of steady-state growth rates and grown at 37°C until an A₆₀₀ of 0.3–0.4. Genomic DNA was harvested from cells and marker frequency analysis was determined using qPCR. The <i>ori:ter</i> ratios are plotted versus growth rate (error bars indicate the standard deviation of three technical replicates). Representative data are shown from a single experiment; an independently performed replicate of the experiment is shown in <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004731#pgen.1004731.s005" target="_blank">Figures S5A-B</a>. Wild-type (HM222), Δ<i>soj</i> (HM227), Δ<i>yabA</i> (HM739), Δ<i>soj</i> Δ<i>yabA</i> (HM741). (<b>B</b>) Growth rate regulation of DNA replication initiation does not require (p)ppGpp. Strains were grown overnight at 37°C in minimal media supplemented with succinate and amino acids (200 µg/ml). The culture was diluted 1∶100 into various media (succinate + amino acids, glycerol + amino acids, LB, PAB) to generate a range of steady-state growth rates and grown at 37°C until an A₆₀₀ of 0.2–0.6. Genomic DNA was harvested from cells and marker frequency analysis was determined using qPCR. The <i>ori:ter</i> ratios are plotted versus growth rate (error bars indicate the standard deviation of three technical replicates). Representative data are shown from a single experiment; an independently performed experiment is shown in <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004731#pgen.1004731.s005" target="_blank">Figure S5C</a>. Wild-type (HM222), Δ(p)ppGpp (HM1230).