Mechanistic Analysis of the Pump Cycle of the KdpFABC P-Type ATPase

DC FieldValueLanguage
dc.contributor.authorDamnjanovic, Bojana
dc.contributor.authorWeber, Annemarie
dc.contributor.authorPotschies, Meike
dc.contributor.authorGreie, Joerg-Christian
dc.contributor.authorApell, Hans-Juergen
dc.date.accessioned2021-12-23T16:11:45Z-
dc.date.available2021-12-23T16:11:45Z-
dc.date.issued2013
dc.identifier.issn00062960
dc.identifier.urihttps://osnascholar.ub.uni-osnabrueck.de/handle/unios/9869-
dc.description.abstractThe high-affinity potassium uptake system KdpFABC is a unique type Ia P-type ATPase, because it separates the sites of ATP hydrolysis and ion transport on two different subunits. KdpFABC was expressed in Escherichia coli. It was then isolated and purified to homogeneity to obtain a detergent-solubilized enzyme complex that allowed the analysis of ion binding properties. The electrogenicity and binding affinities of the ion pump for K+ and H+ were determined in detergent-solubilized complexes by means of the electrochromic styryl dye RH421. Half-saturating K+ concentrations and pK values for H+ binding could be obtained in both the unphosphorylated and phosphorylated conformations of KdpFABC. The interaction of both ions with KdpFABC was studied in detail, and the presence of independent binding sites was ascertained. It is proposed that KdpFABC reconstituted in vesicles translocates protons at a low efficiency opposite from the well-established import of K+ into the bacteria. On the basis of our results, various mechanistic pump cycle models were derived from the general Post-Albers scheme of P-type ATPases and discussed in the framework of the experimental evidence to propose a possible molecular pump cycle for KdpFABC.
dc.description.sponsorshipKonstanz Research School of Chemical Biology (University of Konstanz); Deutsche ForschungsgemeinschaftGerman Research Foundation (DFG) [GR2698/1-1]; We gratefully acknowledge funding from the Konstanz Research School of Chemical Biology (University of Konstanz). J.-C.G. was supported by the Deutsche Forschungsgemeinschaft (Grant GR2698/1-1).
dc.language.isoen
dc.publisherAMER CHEMICAL SOC
dc.relation.ispartofBIOCHEMISTRY
dc.subjectBiochemistry & Molecular Biology
dc.subjectCHARGE TRANSLOCATION
dc.subjectCOMPLEX
dc.subjectCYTOPLASMIC-BINDING SITES
dc.subjectESCHERICHIA-COLI
dc.subjectION SELECTIVITY
dc.subjectK+-TRANSPORT
dc.subjectMEMBRANE-POTENTIALS
dc.subjectNA,K-ATPASE
dc.subjectSUBUNIT
dc.subjectTRANSLOCATING KDP-ATPASE
dc.titleMechanistic Analysis of the Pump Cycle of the KdpFABC P-Type ATPase
dc.typejournal article
dc.identifier.doi10.1021/bi400729e
dc.identifier.isiISI:000323471900008
dc.description.volume52
dc.description.issue33
dc.description.startpage5563
dc.description.endpage5576
dc.publisher.place1155 16TH ST, NW, WASHINGTON, DC 20036 USA
dcterms.isPartOf.abbreviationBiochemistry
dcterms.oaStatusGreen Submitted
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