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bioRxiv · 10.1101/254623

A role for a conserved kinase in the transcriptional control of methionine biosynthesis in Escherichia coli experiencing sustained nitrogen starvation

Switzer, A.·Evangelopoulos, D.·Figueira, R.·de Carvalho, L.·Brown, D.·Wigneshweraraj, S.
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Abstract

The initial adaptive transcriptional response to nitrogen (N) starvation in Escherichia coli involves large-scale alterations to the transcriptome mediated by the transcription activator, NtrC. One of the NtrC-activated genes is yeaG, which encodes a conserved bacterial kinase. Although it is known that YeaG is required for optimal survival under sustained N starvation, the molecular basis by which YeaG benefits N starved E. coli remains elusive. By combining transcriptomics with targeted metabolomics analyses, we demonstrate that the methionine biosynthesis pathway becomes transcriptionally dysregulated in{Delta} yeaG bacteria experiencing sustained N starvation. This results in the aberrant and energetically costly biosynthesis of methionine and associated metabolites under sustained N starvation with detrimental consequences to cell viability. It appears the activity of the master transcriptional repressor of methionine biosynthesis genes, MetJ, is compromised in{Delta} yeaG bacteria under sustained N starvation, resulting in transcriptional derepression of MetJ-regulated genes. The results suggest that YeaG is a novel regulatory factor and functions as a molecular brake in the transcriptional control of both the NtrC-regulon and methionine biosynthesis genes in E. coli experiencing sustained N starvation.

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Switzer, A., Evangelopoulos, D., Figueira, R., de Carvalho, L., Brown, D., Wigneshweraraj, S.. 2018-01-27. A role for a conserved kinase in the transcriptional control of methionine biosynthesis in Escherichia coli experiencing sustained nitrogen starvation. https://doi.org/10.1101/254623

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