Assessment of the interaction between the flux-signaling metabolite fructose-1,6-bisphosphate and the bacterial transcription factors CggR and Cra

Brenda Bley Folly, Alvaro D Ortega*, Georg Hubmann, Silke Bonsing-Vedelaar, Hein J Wijma, Pieter van der Meulen, Andreas Milias-Argeitis, Matthias Heinemann*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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Abstract

Bacteria regulate cell physiology in response to extra- and intracellular cues. Recent work showed that metabolic fluxes are reported by specific metabolites, whose concentrations correlate with flux through the respective metabolic pathway. An example of a flux-signaling metabolite is fructose-1,6-bisphosphate (FBP). In turn, FBP was proposed to allosterically regulate master regulators of carbon metabolism, Cra in Escherichia coli and CggR in Bacillus subtilis. However, a number of questions on the FBP-mediated regulation of these transcription factors is still open. Here, using thermal shift assays and microscale thermophoresis we demonstrate that FBP does not bind Cra, even at millimolar physiological concentration, and with electrophoretic mobility shift assays we also did not find FBP-mediated impairment of Cra's affinity for its operator site, while fructose-1-phosphate does. Furthermore, we show for the first time that FBP binds CggR within the millimolar physiological concentration range of the metabolite, and decreases DNA-binding activity of this transcription factor. Molecular docking experiments only identified a single FBP binding site CggR. Our results provide the long thought after clarity with regards to regulation of Cra activity in E. coli and reveals that E. coli and B. subtilis use distinct cellular mechanism to transduce glycolytic flux signals into transcriptional regulation. This article is protected by copyright. All rights reserved.

Original languageEnglish
Pages (from-to)278-290
Number of pages13
JournalMolecular Microbiology
Volume109
Issue number3
Early online date20-Jun-2018
DOIs
Publication statusPublished - Aug-2018

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