Routes of phosphoryl group transfer during signal transmission and signal decay in the dimeric sensor histidine kinase ArcB

Juan L. Teran-Melo, Gabriela R. Peña-Sandoval, Hortencia Silva-Jimenez, Claudia Rodriguez, Adrián F. Alvarez, Dimitris Georgellis
2018 Journal of Biological Chemistry  
The Arc (anoxic redox control) two-component system of Escherichia coli, comprising ArcA as the response regulator and ArcB as the sensor histidine kinase, modulates the expression of numerous genes in response to respiratory growth conditions. Under reducing growth conditions, ArcB autophosphorylates at the expense of ATP, and transphosphorylates ArcA via a His 292 3 Asp 576 3 His 717 3 Asp 54 phosphorelay, whereas under oxidizing growth conditions, ArcB catalyzes the dephosphorylation of
more » ... phorylation of ArcA-P by a reverse Asp 54 3 His 717 3 Asp 576 3 P i phosphorelay. However, the exact phosphoryl group transfer routes and the molecular mechanisms determining their directions are unclear. Here, we show that, during signal propagation, the His 292 3 Asp 576 and Asp 576 3 His 717 phosphoryl group transfers within ArcB dimers occur intra-and intermolecularly, respectively. Moreover, we report that, during signal decay, the phosphoryl group transfer from His 717 to Asp 576 takes place intramolecularly. In conclusion, we present a mechanism that dictates the direction of the phosphoryl group transfer within ArcB dimers and that enables the discrimination of the kinase and phosphatase activities of ArcB.
doi:10.1074/jbc.ra118.003910 pmid:29945971 fatcat:4xagycdbifbidaiwli3mppytta