Metabolomics reveals that the cAMP receptor protein regulates nitrogen and peptidoglycan synthesis in .

requires extensive sensing and response to environment for its successful survival and pathogenesis, and signalling by cyclic adenosine 3',5'-monophosphate (cAMP) is an important mechanism. cAMP regulates expression of target genes interaction with downstream proteins, one of which is cAMP receptor protein (CRP), a global transcriptional regulator. Previous genomic works had identified regulon of CRP and investigated transcriptional changes in deletion mutant, however a link to downstream metabolomic events were lacking, which would help better understand roles of CRP. This work aims at investigating changes at metabolome level in deletion mutant combining untargeted LC-MS analysis and C isotope tracing analysis. The results were compared with previously published RNA sequencing data. We identified increasing abundances of metabolites related to nitrogen metabolism including ornithine, citrulline and glutamate derivatives, while C isotope labelling analysis further showed changes in turnover of these metabolites and amino acids, suggesting regulatory roles of CRP in nitrogen metabolism. Upregulation of diaminopimelic acid and its related genes also suggested role of CRP in regulation of peptidoglycan synthesis. This study provides insights on metabolomic aspects of cAMP-CRP regulatory pathway in and links to previously published transcriptomic data drawing a more complete map.