Functional & Integrative Genomics

, Volume 7, Issue 3, pp 229–255

Genome-wide expression profiling in Geobacter sulfurreducens: identification of Fur and RpoS transcription regulatory sites in a relGsu mutant

  • Julia Krushkal
  • Bin Yan
  • Laurie N. DiDonato
  • Marko Puljic
  • Kelly P. Nevin
  • Trevor L. Woodard
  • Ronald M. Adkins
  • Barbara A. Methé
  • Derek R. Lovley
Original Paper

DOI: 10.1007/s10142-007-0048-5

Cite this article as:
Krushkal, J., Yan, B., DiDonato, L.N. et al. Funct Integr Genomics (2007) 7: 229. doi:10.1007/s10142-007-0048-5

Abstract

RelGsu is the single Geobacter sulfurreducens homolog of RelA and SpoT proteins found in many organisms. These proteins are involved in the regulation of levels of guanosine 3′, 5′ bispyrophosphate, ppGpp, a molecule that signals slow growth and stress response under nutrient limitation in bacteria. We used information obtained from genome-wide expression profiling of the relGsu deletion mutant to identify putative regulatory sites involved in transcription networks modulated by RelGsu or ppGpp. Differential gene expression in the relGsu deletion mutant, as compared to the wild type, was available from two growth conditions, steady state chemostat cultures and stationary phase batch cultures. Hierarchical clustering analysis of these two datasets identified several groups of operons that are likely co-regulated. Using a search for conserved motifs in the upstream regions of these co-regulated operons, we identified sequences similar to Fur- and RpoS-regulated sites. These findings suggest that Fur- and RpoS-dependent gene expression in G. sulfurreducens is affected by RelGsu-mediated signaling.

Keywords

Guanosine 3′,5′ bispyrophosphate ppGpp RelA Promoter 

Supplementary material

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Julia Krushkal
    • 1
  • Bin Yan
    • 1
    • 5
  • Laurie N. DiDonato
    • 2
  • Marko Puljic
    • 1
  • Kelly P. Nevin
    • 2
  • Trevor L. Woodard
    • 2
  • Ronald M. Adkins
    • 4
  • Barbara A. Methé
    • 3
  • Derek R. Lovley
    • 2
  1. 1.Department of Preventive MedicineUniversity of Tennessee Health Science CenterMemphisUSA
  2. 2.Department of Microbiology, Morrill Science Center IV NorthUniversity of MassachusettsAmherstUSA
  3. 3.The Institute for Genomic ResearchRockvilleUSA
  4. 4.Department of PediatricsUniversity of Tennessee Health Science CenterMemphisUSA
  5. 5.NIDCD, National Institutes of HealthBethesdaUSA

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