Possible models for Rba effects on RcGTA gene expression. Transcript levels of the genes encoding RbaY, RbaV and RbaW are >2-fold lower in the absence of the response regulator CtrA (grey arrow) . The predicted phosphatase RbaY is proposed to activate the STAS domain-containing RbaV (black arrow) by dephosphorylation in response to signal(s) from an unknown sensor kinase(s) (SKs) (grey arrow). There are then two possible scenarios that result in increased RcGTA gene expression. 1. Dephosphorylation of RbaV allows it to activate undetermined intermediaries (X; black arrow) to increase RcGTA gene expression (grey arrow). In this scenario, the predicted kinase RbaW would serve as an inhibitor of RbaV. 2. Dephosphorylation of RbaV allows it to interact with RbaW to relieve inhibition of an unidentified σ factor that promotes transcription of the RcGTA gene cluster (black arrow). Our data support model 1.
Mercer and Lang BMC Microbiology 2014 14:71 doi:10.1186/1471-2180-14-71