The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)

The autoregulatory role of EsaR, a quorum-sensing regulator in Pantoea stewartii ssp. stewartii: evidence for a repressor function.

Capsular polysaccharide synthesis and virulence in the plant pathogenic bacterium Pantoea stewartii ssp. stewartii requires the quorum-sensing regulatory proteins, EsaR and EsaI, and the diffusible inducer N-(3-oxo-hexanoyl)-L-homoserine lactone. Prior mutational studies suggested that EsaR might function as a repressor of quorum sensing in the control of capsular polysaccharide synthesis. Further, a lux box-like palindromic sequence coinciding with the putative -10 element of the esaR promoter suggested a possible negative autoregulatory role for EsaR. This report presents genetic evidence that EsaR represses the esaR gene under inducer-limiting conditions, and that addition of inducer promotes rapid, dose-dependent derepression. DNA mobility-shift assays and analyses by surface plasmon resonance refractometry show that EsaR binds target DNAs in a ligand-free state, and that inducer alters the binding characteristics of EsaR. Physical measurements indicate that the EsaR protein binds N-(3-oxo-hexanoyl)-L-homoserine lactone, in a 1:1 protein:ligand ratio, and that inducer binding enhances the thermal stability of the EsaR protein. These combined genetic and biochemical data establish that EsaR regulates its own expression by signal-independent repression and signal-dependent derepression. Additionally, we provide evidence that EsaR does not govern the expression of the linked esaI gene, thus EsaR has no role in controlling coinducer synthesis.[1]


  1. The autoregulatory role of EsaR, a quorum-sensing regulator in Pantoea stewartii ssp. stewartii: evidence for a repressor function. Minogue, T.D., Wehland-von Trebra, M., Bernhard, F., von Bodman, S.B. Mol. Microbiol. (2002) [Pubmed]
WikiGenes - Universities