Identification of a ubiquinone-binding site that affects autophosphorylation of the sensor kinase RegB.

ABSTRACT: Rhodobacter capsulatus regulates many metabolic processes in response to the level of environmental oxygen and the energy state of the cell. One of the key global redox regulators of the cell's metabolic physiology is the sensor kinase RegB that controls the synthesis of numerous energy generation and utilization processes. In this study, we have succeeded in purifying full-length RegB containing six transmembrane-spanning elements. Exogenous addition of excess oxidized coenzyme Q1 is capable of inhibiting RegB autophosphorylation approximately 6-fold. However, the addition of reduced coenzyme Q1 exhibits no inhibitory effect on kinase activity. A ubiquinone-binding site, as defined by azidoquinone photo affinity cross-linking, was determined to lie within a periplasmic loop between transm

SUBMITTER: Swem LR 

PROVIDER: S-EPMC2776112 | biostudies-literature | 2006 Mar

REPOSITORIES: biostudies-literature