Towards an understanding of the molecular mechanisms of stimulus perception and signal transduction by the KdpD/KdpE system of Escherichia coli.
The membrane-bound histidine kinase KdpD is a putative turgor sensor that regulates, together with the response regulator KdpE, expression of the kdpFABC operon. This operon encodes the high affinity K+-uptake system KdpFABC of Escherichia coli. Expression of kdpFABC is induced under K+ limiting growth conditions and in response to an osmotic upshift. Various structural features of KdpD and KdpE, which are important for stimulus perception and/or signal transduction were identified and are described here. Furthermore, various studies undertaken to elucidate the nature of the stimulus for KdpD result in a new model for KdpD stimulus perception. According to this, autophosphorylation activity of KdpD is not a result of changes in turgor per se. Instead, various--mainly intracellular parameters--that are related to changes of environmental conditions influence the activities of KdpD.
Jung
Kirsten
K
Universität Osnabrück, Fachbereich Biologie/Chemie, Abteilung Mikrobiologie, Germany. jung_k@biologie.uni-osnabrueck.de
Altendorf
Karlheinz
K
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics* / Q000502:physiology; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D009994:Osmolar Concentration; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D015534:Trans-Activators; C075615:kdpE protein, E coli; C489580:KdpD protein, E coli; D011494:Protein Kinases; C075616:kdpD protein, Bacteria