LurR is a regulator of the central lactate oxidation pathway in sulfate-reducing Desulfovibrio species

PLoS One. 2019 Apr 9;14(4):e0214960. doi: 10.1371/journal.pone.0214960. eCollection 2019.

Abstract

The central carbon/lactate utilization pathway in the model sulfate-reducing bacterium, Desulfovibrio vulgaris Hildenborough, is encoded by the highly conserved operon DVU3025-3033. Our earlier in vitro genome-wide study had suggested a network of four two-component system regulators that target this large operon; however, how these four regulators control this operon was not known. Here, we probe the regulation of the lactate utilization operon with mutant strains and DNA-protein binding assays. We show that the LurR response regulator is required for optimal growth and complete lactate utilization, and that it activates the DVU3025-3033 lactate oxidation operon as well as DVU2451, a lactate permease gene, in the presence of lactate. We show by electrophoretic mobility shift assays that LurR binds to three sites in the upstream region of DVU3025, the first gene of the operon. NrfR, a response regulator that is activated under nitrite stress, and LurR share similar binding site motifs and bind the same sites upstream of DVU3025. The DVU3025 promoter also has a binding site motif (Pho box) that is bound by PhoB, a two-component response regulator activated under phosphate limitation. The lactate utilization operon, the regulator LurR, and LurR binding sites are conserved across the order Desulfovibrionales whereas possible modulation of the lactate utilization genes by additional regulators such as NrfR and PhoB appears to be limited to D. vulgaris.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Bacterial Proteins* / genetics
  • Bacterial Proteins* / metabolism
  • Desulfovibrio vulgaris* / genetics
  • Desulfovibrio vulgaris* / metabolism
  • Genome-Wide Association Study
  • Lactic Acid / metabolism*
  • Nucleotide Motifs
  • Operon*
  • Oxidation-Reduction
  • Response Elements*
  • Species Specificity
  • Transcription Factors* / genetics
  • Transcription Factors* / metabolism

Substances

  • Bacterial Proteins
  • Transcription Factors
  • Lactic Acid

Grants and funding

This work was part of the ENIGMA, Ecosystems and Networks Integrated with Genes and Molecular Assemblies (http://enigma.lbl.gov), a Scientific Focus Area Program at Lawrence Berkeley National Laboratory and is supported by the U.S. Department of Energy, Office of Science, Office of Biological & Environmental Research under contract number DE-AC02-454 05CH11231 between Lawrence Berkeley National Laboratory and the U. S. Department of Energy. The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.