Membrane Region M-2C2 in Subunit KtrB of the K+ Uptake System KtrAB from Vibrio alginolyticus Forms a Flexible Gate Controlling K+ Flux AN ELECTRON PARAMAGNETIC RESONANCE STUDY

DC FieldValueLanguage
dc.contributor.authorHaenelt, Inga
dc.contributor.authorWunnicke, Dorith
dc.contributor.authorMueller-Trimbusch, Meike
dc.contributor.authorVor der Brueggen, Marc
dc.contributor.authorKraus, Inga
dc.contributor.authorBakker, Evert P.
dc.contributor.authorSteinhoff, Heinz-Juergen
dc.date.accessioned2021-12-23T16:11:57Z-
dc.date.available2021-12-23T16:11:57Z-
dc.date.issued2010
dc.identifier.urihttps://osnascholar.ub.uni-osnabrueck.de/handle/unios/9970-
dc.description.abstractTransmembrane stretch M-2C from the bacterial K+-translocating protein KtrB is unusually long. In its middle part, termed M-2C2, it contains several small and polar amino acids. This region is flanked by the two alpha-helices M-2C1 and M-2C3 and may form a flexible gate at the cytoplasmic side of the membrane controlling K+ translocation. In this study, we provide experimental evidence for this notion by using continuous wave and pulse EPR measurements of single and double spin-labeled cysteine variants of KtrB. Most of the spin-labeled residues in M-2C2 were shown to be immobile, pointing to a compact structure. However, the high polarity revealed for the microenvironment of residue positions 317, 318, and 327 indicated the existence of a water-accessible cavity. Upon the addition of K+ ions, M2C2 residue Thr-318R1 (R1 indicates the bound spin label) moved with respect to M-2B residue Asp-222R1 and M2C3 residue Val-331R1 but not with respect to M2C1 residue Met-311R1. Based on distances determined between spin-labeled residues of double-labeled variants of KtrB in the presence and absence of K+ ions, structural models of the open and closed conformations were developed.
dc.description.sponsorshipDeutsche ForschungsgemeinschaftGerman Research Foundation (DFG) [SFB431]; This work was supported by the Deutsche Forschungsgemeinschaft SFB431 (projects P6 and P18).
dc.language.isoen
dc.publisherAMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
dc.relation.ispartofJOURNAL OF BIOLOGICAL CHEMISTRY
dc.subjectAMINO-ACID SUBSTITUTIONS
dc.subjectBiochemistry & Molecular Biology
dc.subjectCRYSTAL-STRUCTURE
dc.subjectDISTANCE MEASUREMENTS
dc.subjectESCHERICHIA-COLI K-12
dc.subjectFULL-LENGTH KCSA
dc.subjectGLYCINE RESIDUES
dc.subjectHIGH-AFFINITY
dc.subjectION CHANNEL
dc.subjectKDPFABC COMPLEX
dc.subjectPOTASSIUM-TRANSPORT
dc.titleMembrane Region M-2C2 in Subunit KtrB of the K+ Uptake System KtrAB from Vibrio alginolyticus Forms a Flexible Gate Controlling K+ Flux AN ELECTRON PARAMAGNETIC RESONANCE STUDY
dc.typejournal article
dc.identifier.doi10.1074/jbc.M110.139311
dc.identifier.isiISI:000281404100064
dc.description.volume285
dc.description.issue36
dc.description.startpage28210
dc.description.endpage28219
dc.contributor.orcid0000-0003-1495-3163
dc.contributor.orcid0000-0002-5888-0157
dc.contributor.researcheridN-2982-2016
dc.contributor.researcheridH-3791-2014
dc.identifier.eissn1083351X
dc.publisher.place9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA
dcterms.isPartOf.abbreviationJ. Biol. Chem.
dcterms.oaStatusGreen Published, hybrid
crisitem.author.deptFB 04 - Physik-
crisitem.author.deptidfb04-
crisitem.author.parentorgUniversität Osnabrück-
crisitem.author.netidStHe633-
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