Delta-arcS versus wild-type

ABSTRACT: The availability of oxygen is a major environmental factor for many microbes, in particular for bacteria, such as Shewanella species, which thrive in redox-stratified environments. One of the best studied systems involved in mediating the response to changes in environmental oxygen levels is the Arc two-component system of Escherichia coli, consisting of the sensor kinase ArcB and the cognate response regulator ArcA. An ArcA ortholog was previously identified in Shewanella, and as in E. coli, Shewanella ArcA is involved in regulating the response to shifts in oxygen levels. Here, we identified the hybrid sensor kinase SO_0577, now designated ArcS, as the previously elusive cognate sensor kinase of the Arc system in S. oneidensis MR-1. Phenotypic mutant characterization, transcriptomic analysis, protein-protein interaction and phosphotransfer studies revealed that the Shewanella Arc system consists of the sensor kinase ArcS, the single phosphotransfer domain protein HptA, and the response regulator ArcA. Phylogenetic analysis suggests that HptA might be a relict of ArcB. Conversely, ArcS is substantially different with respect to overall sequence homologies and domain organization. Thus, we speculate ArcS might have adopted the role of ArcB after loss of the original sensor kinase, perhaps as a consequence of regulatory adaptation to a redox-stratified environment. In the study presented, expression profiles of three independent replicates of Shewanella oneidensis MR-1 delta-arcS were compared to three independent replicates of Shewanella oneidensis MR-1 wild type cells. All samples were obtained from exponentially aerobically grown cells in LB

ORGANISM(S): Shewanella oneidensis MR-1

SUBMITTER: Kai Thormann 

PROVIDER: E-GEOD-21044 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress