vitamin-k-semiquinone-radical and ubiquinone-8

The Arc two-component signal transduction system mediates adaptive responses of Escherichia coli to changing respiratory conditions of growth. Under anaerobic conditions, the ArcB sensor kinase autophosphorylates and then transphosphorylates ArcA, a global transcriptional regulator that controls the expression of numerous operons involved in respiratory or fermentative metabolism. We show that oxidized forms of quinone electron carriers act as direct negative signals that inhibit autophosphorylation of ArcB during aerobiosis. Thus, the Arc signal transduction system provides a link between the electron transport chain and gene expression.

Topics: Aerobiosis; Bacterial Outer Membrane Proteins; Electron Transport; Escherichia coli; Escherichia coli Proteins; Gene Expression Regulation, Bacterial; Membrane Proteins; Mutation; Oxidation-Reduction; Phosphorylation; Protein Kinases; Quinones; Repressor Proteins; Signal Transduction; Ubiquinone; Vitamin K; Vitamin K 2