Krushkal J, Yan B, DiDonato LN, Puljic M, Nevin KP, Woodard TL et al.. Genome-wide expression profiling in Geobacter sulfurreducens: identification of Fur and RpoS transcription regulatory sites in a relGsu mutant. Funct Integr Genomics 7: 229-255

ArticleinFunctional and Integrative Genomics 7(3):229-55 · August 2007with7 Reads
Impact Factor: 2.48 · DOI: 10.1007/s10142-007-0048-5 · Source: PubMed


    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 rel
    deletion mutant to identify putative regulatory sites involved in transcription networks modulated by RelGsu or ppGpp. Differential gene expression in the rel
    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.