Phenolic Amides Are Potent Inhibitors ofDe NovoNucleotide Biosynthesis

• DOI: 10.1128/aem.01324-15
• Publication Date: 2015-06-13T03:30:53Z
• Authors: Tippapha Pisithkul; Tyler B. Jacobson; Thomas J. O'Brien; David M. Stevenson; Daniel Amador-Noguez
• Keywords: Glutamine amidotransferase; Pyrimidine metabolism; Metabolic pathway; Amide; Purine metabolism

ABSTRACT An outstanding challenge toward efficient production of biofuels and value-added chemicals from plant biomass is the impact that lignocellulose-derived inhibitors have on microbial fermentations. Elucidating mechanisms underlie their toxicity critical for developing strategies to overcome them. Here, using Escherichia coli as a model system, we investigated metabolic effects feruloyl amide coumaroyl amide, predominant phenolic compounds in ammonia-pretreated hydrolysates. Using metabolomics, isotope tracers, biochemical assays, showed these two amides act potent fast-acting purine pyrimidine biosynthetic pathways. Feruloyl or exposure leads (i) rapid buildup 5-phosphoribosyl-1-pyrophosphate (PRPP), key precursor nucleotide biosynthesis, (ii) decrease levels intermediates, (iii) long-term generalized deoxynucleotide levels. Tracer experiments 13 C-labeled sugars [ 15 N]ammonia demonstrated carbon nitrogen fluxes into nucleotides deoxynucleotides are inhibited by amides. We found mediated via direct inhibition glutamine amidotransferases participate In particular, competitive inhibitor PRPP amidotransferase (PurF), which catalyzes first committed step de novo biosynthesis. Finally, external nucleoside supplementation prevents amide-mediated growth allowing biosynthesis salvage The results presented here will help development facilitate engineering more producers chemicals.