The extension of the fourth transmembrane helix of the sensor kinase KdpD of Escherichia coli is involved in sensing

DC FieldValueLanguage
dc.contributor.authorZimmann, Petra
dc.contributor.authorSteinbruegge, Anne
dc.contributor.authorSchniederberend, Maren
dc.contributor.authorJung, Kirsten
dc.contributor.authorAltendorf, Karlheinz
dc.date.accessioned2021-12-23T16:11:05Z-
dc.date.available2021-12-23T16:11:05Z-
dc.date.issued2007
dc.identifier.issn00219193
dc.identifier.urihttps://osnascholar.ub.uni-osnabrueck.de/handle/unios/9518-
dc.description.abstractThe KdpD sensor kinase and the KdpE response regulator control expression of the kdpFABC operon coding for the KdpFABC high-affinity K+ transport system of Escherichia coli. In search of a distinct part of the input domain of KdpD which is solely responsible for K+ sensing, sequences of kdpD encoding the transmembrane region and adjacent N-terminal and C-terminal extensions were subjected to random mutagenesis. Nine KdpD derivatives were identified that had lost tight regulation of kdpFABC expression. They all carried single amino acid replacements located in a region encompassing the fourth transmembrane helix and the adjacent arginine cluster of KdpD. All mutants exhibited high levels of kdpFABC expression regardless of the external K+ concentration. However, 3- to 14-fold induction was observed under extreme K+-limiting conditions and in response to an osmotic upshift when sucrose was used as an osmollyte. These KdpD derivatives were characterized by a reduced phosphatase activity in comparison to the autokinase activity in vitro, which explains constitutive expression. Whereas for wild-type KdpD the autokinase activity and also, in turn, the phosphotransfer activity to KdpE were inhibited by increasing concentrations of K+, both activities were unaffected in the KdpD derivatives. These data clearly show that the extension of the fourth transmembrane helix encompassing the arginine cluster is mainly involved in sensing both K+ limitation and osmotic upshift, which may not be separated mechanistically.
dc.language.isoen
dc.publisherAMER SOC MICROBIOLOGY
dc.relation.ispartofJOURNAL OF BACTERIOLOGY
dc.subjectATPASE
dc.subjectC-TERMINAL DOMAIN
dc.subjectEXPRESSION
dc.subjectK+
dc.subjectMicrobiology
dc.subjectOPERON
dc.subjectOSMOTIC CONTROL
dc.subjectPHOSPHATASE-ACTIVITY
dc.subjectPOTASSIUM
dc.subjectPROTEIN
dc.subjectTURGOR SENSOR
dc.titleThe extension of the fourth transmembrane helix of the sensor kinase KdpD of Escherichia coli is involved in sensing
dc.typejournal article
dc.identifier.doi10.1128/JB.00976-07
dc.identifier.isiISI:000250100000019
dc.description.volume189
dc.description.issue20
dc.description.startpage7326
dc.description.endpage7334
dc.identifier.eissn10985530
dc.publisher.place1752 N ST NW, WASHINGTON, DC 20036-2904 USA
dcterms.isPartOf.abbreviationJ. Bacteriol.
dcterms.oaStatusGreen Published, Bronze
crisitem.author.deptFB 05 - Biologie/Chemie-
crisitem.author.deptidfb05-
crisitem.author.parentorgUniversität Osnabrück-
crisitem.author.netidAlKa770-
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