FIG 5.

dPN increases the AIRs requirement for ThiC-dependent thiamine synthesis. (a) Thiamine and purine biosynthesis and salvage in S. enterica. Each arrow represents a biochemical reaction, and relevant enzymes are indicated next to the arrows. The DM7060 background carries lesions in genes that encode proteins in red. Blue indicates radical AdoMet enzymes that utilize iron-sulfur clusters. Compounds accompanied by chemical structures were used in subsequent feeding experiments. (b and c) Molten soft agar (0.7% [wt/vol]) inoculated with purGE stm4068 ptsJ culture (DM17274) was overlaid on minimal NCE glucose containing 0.4 mM adenine in the absence (b) or presence (c) of 0.1 μM dPN. Other supplementation was added by spotting 1 μL of AIRs (∼300 mM), thiamine (0.1 mM), HMP (0.1 mM), and THZ (0.1 mM) on top of the solidified soft agar layer. Representative growth from three independent experiments is shown. PRPP, phosphoribosyl pyrophosphate; HMP-PP, 4-amino-5-hydroxymethyl-2-methylpyrimidine diphosphate; THZ-P, 4-methyl-5-(2-hydroxyethyl)-thiazole phosphate; TMP, thiamine monophosphate; TPP, thiamine pyrophosphate; Gln, l-glutamine; Tyr, l-tyrosine; Cys, l-cysteine.