Redox Responding Sensor Kinases
Jiang Wu, Vladimira Dragnea and Carl Bauer
from: Two-Component Systems in Bacteria (Edited by: Roy Gross and Dagmar Beier). Caister Academic Press, U.K. (2012)
Sensor kinases that respond to changes in redox have been described in several bacterial systems. This review is centered on the molecular mechanism of redox sensing in a select group of sensor kinases that have been well-defined biochemically. We cover the role of oxidized ubiquinone and redox active cysteine in controlling the kinase activity of the sensor kinases RegB and ArcB of Rhodobacter capsulatus and Escherichia coli, respectively. We also review inhibition of kinase activity that occurs upon the binding of dioxygen to heme to a PAS domain in FixL of rhizobia and upon the binding of dioxygen to heme to a GAF domain in DosT of Mycobacterium tuberculosis. Finally, we discuss recent evidence that the photoreceptor LovK of Caulobacter crescentus contains a redox active flavin that when reduced inhibits the ability of LovK to undergo a photocycle that regulates kinase activity read more ...