Link between the Δ<i>hfq</i> phenotypes and the biosynthesis of pantothenate and CoA.

<p>(A) Schematic of the pantothenate and CoA biosynthesis pathway in <i>C</i>. <i>crescentus</i>. The solid arrows represent a single enzymatic step, while the dashed arrows denote multiple enzymatic steps. PanD and VOR are the only two enzymes in this pathway whose mRNA levels were affected by the <i>hfq</i> deletion. (B) <i>panD</i> and <i>vor</i> mRNA levels in the WT and Δ<i>hfq</i> strains measured in RNA-Seq experiments. The error bars represent the standard deviations from 3 biological replicates. (C) Proposed mechanism underlying KG accumulation in Δ<i>hfq</i> cells. Downregulation of <i>panD</i> expression and upregulation of <i>vor</i> expression lead to reduction in CoA abundance. In turn, lower CoA level reduces KGDH activity leading to KG accumulation. Inactivation of <i>vor</i> in the Δ<i>hfq vor</i>::Tn<i>5</i> suppressor strain partially restores CoA synthesis and improves KGDH activity, resulting in lower KG levels. (D) Phase contrast images of Δ<i>hfq</i> cells grown in PYE with or without 1 mM pantothenate (Pan) for 20 h at 30°C. (E) Scatter plots of cell lengths and widths of populations described in (D). (F) Growth curves of WT and Δ<i>hfq</i> strains cultured at 30°C in PYE with and without 1 mM Pan. Each curve represents the average of 3 replicates with the standard deviation shown in grey.</p>