Conformational Dynamics in the Selectivity Filter of KcsA in Response to Potassium Ion Concentration
Conformational change in the selectivity filter of KcsA as a function of ambient potassium concentration is studied with solid-state NMR. This highly conserved region of the protein is known to chelate potassium ions selectively. We report solid-state NMR chemical shift fingerprints of two distinct...
Gespeichert in:
| Veröffentlicht in: | Journal of molecular biology 2010-08, Vol.401 (2), p.155-166 |
|---|---|
| Hauptverfasser: | , , , |
| Format: | Artikel |
| Sprache: | eng |
| Schlagworte: | |
| Online-Zugang: | Volltext |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| container_end_page | 166 |
|---|---|
| container_issue | 2 |
| container_start_page | 155 |
| container_title | Journal of molecular biology |
| container_volume | 401 |
| creator | Bhate, Manasi P. Wylie, Benjamin J. Tian, Lin McDermott, Ann E. |
| description | Conformational change in the selectivity filter of KcsA as a function of ambient potassium concentration is studied with solid-state NMR. This highly conserved region of the protein is known to chelate potassium ions selectively. We report solid-state NMR chemical shift fingerprints of two distinct conformations of the selectivity filter; significant changes are observed in the chemical shifts of key residues in the filter as the potassium ion concentration is changed from 50 mM to 1 μM. Potassium ion titration studies reveal that the site-specific Kd for K+ binding at the key pore residue Val76 is on the order of ∼7 μM and that a relatively high sample hydration is necessary to observe the low-K+ conformer. Simultaneous detection of both conformers at low ambient potassium concentration suggests that the high-K+ and low-K+ states are in slow exchange on the NMR timescale (kex |
| doi_str_mv | 10.1016/j.jmb.2010.06.031 |
| format | Article |
| fullrecord | <record><control><sourceid>proquest_pubme</sourceid><recordid>TN_cdi_pubmedcentral_primary_oai_pubmedcentral_nih_gov_2937177</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><els_id>S0022283610006479</els_id><sourcerecordid>748966734</sourcerecordid><originalsourceid>FETCH-LOGICAL-c516t-5d1f0e2b4bd611619fb4689cab29043f7be65b460ae552aecfc8ae878fcae0983</originalsourceid><addsrcrecordid>eNp9kU1v1DAQhi1ERZfCD-CCfOOUZWwnjiMkpGqhH2olEB9ny3HG1KskXmzvSvvv8bKlai-cLNvvPDOah5A3DJYMmHy_Xq6nfsmh3EEuQbBnZMFAdZWSQj0nCwDOK66EPCUvU1oDQCNq9YKccpAAjIsFGVZhdiFOJvswm5F-2s9m8jZRP9N8h_Q7jmiz3_m8pxd-zBhpcPTGpvND4humTZgT0hzo15BNSn470esw04K1OOf4l_uKnDgzJnx9f56Rnxeff6yuqtsvl9er89vKNkzmqhmYA-R93Q-SMck619dSddb0vINauLZH2ZQnMNg03KB1VhlUrXLWIHRKnJGPR-5m2084HAcY9Sb6ycS9Dsbrpz-zv9O_wk7zTrSsbQvg3T0ght9bTFlPPlkcRzNj2Cbd1qqTshV1SbJj0saQUkT30IWBPsjRa13k6IMcDVIXOaXm7ePxHir-2SiBD8cAliXtPEadrMeyyMHHYkEPwf8H_wc57aJY</addsrcrecordid><sourcetype>Open Access Repository</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype><pqid>748966734</pqid></control><display><type>article</type><title>Conformational Dynamics in the Selectivity Filter of KcsA in Response to Potassium Ion Concentration</title><source>MEDLINE</source><source>Elsevier ScienceDirect Journals Complete</source><creator>Bhate, Manasi P. ; Wylie, Benjamin J. ; Tian, Lin ; McDermott, Ann E.</creator><creatorcontrib>Bhate, Manasi P. ; Wylie, Benjamin J. ; Tian, Lin ; McDermott, Ann E.</creatorcontrib><description>Conformational change in the selectivity filter of KcsA as a function of ambient potassium concentration is studied with solid-state NMR. This highly conserved region of the protein is known to chelate potassium ions selectively. We report solid-state NMR chemical shift fingerprints of two distinct conformations of the selectivity filter; significant changes are observed in the chemical shifts of key residues in the filter as the potassium ion concentration is changed from 50 mM to 1 μM. Potassium ion titration studies reveal that the site-specific Kd for K+ binding at the key pore residue Val76 is on the order of ∼7 μM and that a relatively high sample hydration is necessary to observe the low-K+ conformer. Simultaneous detection of both conformers at low ambient potassium concentration suggests that the high-K+ and low-K+ states are in slow exchange on the NMR timescale (kex<500 s−1). The slow rate and tight binding for evacuating both inner sites simultaneously differ from prior observations in detergent in solution, but agree well with measurements by electrophysiology and appear to result from our use of a hydrated bilayer environment. These observations strongly support a common assumption that the low-K+ state is not involved in ion transmission, and that during transmission one of the two inner sites is always occupied. On the other hand, these kinetic and thermodynamic characteristics of the evacuation of the inner sites certainly could be compatible with participation in a control mechanism at low ion concentration such as C-type inactivation, a process that is coupled to activation and involves closing of the outer mouth of the channel.</description><identifier>ISSN: 0022-2836</identifier><identifier>EISSN: 1089-8638</identifier><identifier>DOI: 10.1016/j.jmb.2010.06.031</identifier><identifier>PMID: 20600123</identifier><language>eng</language><publisher>Netherlands: Elsevier Ltd</publisher><subject>Bacterial Proteins - chemistry ; Bacterial Proteins - genetics ; Bacterial Proteins - metabolism ; Binding Sites ; conformational dynamics ; KcsA ; Kinetics ; Models, Molecular ; Molecular Dynamics Simulation ; Nuclear Magnetic Resonance, Biomolecular ; Potassium - metabolism ; potassium channel ; Potassium Channels - chemistry ; Potassium Channels - genetics ; Potassium Channels - metabolism ; Protein Conformation ; Recombinant Proteins - chemistry ; Recombinant Proteins - genetics ; Recombinant Proteins - metabolism ; selectivity filter ; solid-state NMR ; Spectrum Analysis ; Streptomyces lividans - genetics ; Streptomyces lividans - metabolism ; Water - chemistry</subject><ispartof>Journal of molecular biology, 2010-08, Vol.401 (2), p.155-166</ispartof><rights>2010 Elsevier Ltd</rights><rights>Copyright (c) 2010 Elsevier Ltd. All rights reserved.</rights><rights>2010 Elsevier Ltd. All rights reserved. 2010</rights><lds50>peer_reviewed</lds50><oa>free_for_read</oa><woscitedreferencessubscribed>false</woscitedreferencessubscribed><citedby>FETCH-LOGICAL-c516t-5d1f0e2b4bd611619fb4689cab29043f7be65b460ae552aecfc8ae878fcae0983</citedby><cites>FETCH-LOGICAL-c516t-5d1f0e2b4bd611619fb4689cab29043f7be65b460ae552aecfc8ae878fcae0983</cites></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><linktohtml>$$Uhttps://www.sciencedirect.com/science/article/pii/S0022283610006479$$EHTML$$P50$$Gelsevier$$H</linktohtml><link.rule.ids>230,314,776,780,881,3537,27901,27902,65534</link.rule.ids><backlink>$$Uhttps://www.ncbi.nlm.nih.gov/pubmed/20600123$$D View this record in MEDLINE/PubMed$$Hfree_for_read</backlink></links><search><creatorcontrib>Bhate, Manasi P.</creatorcontrib><creatorcontrib>Wylie, Benjamin J.</creatorcontrib><creatorcontrib>Tian, Lin</creatorcontrib><creatorcontrib>McDermott, Ann E.</creatorcontrib><title>Conformational Dynamics in the Selectivity Filter of KcsA in Response to Potassium Ion Concentration</title><title>Journal of molecular biology</title><addtitle>J Mol Biol</addtitle><description>Conformational change in the selectivity filter of KcsA as a function of ambient potassium concentration is studied with solid-state NMR. This highly conserved region of the protein is known to chelate potassium ions selectively. We report solid-state NMR chemical shift fingerprints of two distinct conformations of the selectivity filter; significant changes are observed in the chemical shifts of key residues in the filter as the potassium ion concentration is changed from 50 mM to 1 μM. Potassium ion titration studies reveal that the site-specific Kd for K+ binding at the key pore residue Val76 is on the order of ∼7 μM and that a relatively high sample hydration is necessary to observe the low-K+ conformer. Simultaneous detection of both conformers at low ambient potassium concentration suggests that the high-K+ and low-K+ states are in slow exchange on the NMR timescale (kex<500 s−1). The slow rate and tight binding for evacuating both inner sites simultaneously differ from prior observations in detergent in solution, but agree well with measurements by electrophysiology and appear to result from our use of a hydrated bilayer environment. These observations strongly support a common assumption that the low-K+ state is not involved in ion transmission, and that during transmission one of the two inner sites is always occupied. On the other hand, these kinetic and thermodynamic characteristics of the evacuation of the inner sites certainly could be compatible with participation in a control mechanism at low ion concentration such as C-type inactivation, a process that is coupled to activation and involves closing of the outer mouth of the channel.</description><subject>Bacterial Proteins - chemistry</subject><subject>Bacterial Proteins - genetics</subject><subject>Bacterial Proteins - metabolism</subject><subject>Binding Sites</subject><subject>conformational dynamics</subject><subject>KcsA</subject><subject>Kinetics</subject><subject>Models, Molecular</subject><subject>Molecular Dynamics Simulation</subject><subject>Nuclear Magnetic Resonance, Biomolecular</subject><subject>Potassium - metabolism</subject><subject>potassium channel</subject><subject>Potassium Channels - chemistry</subject><subject>Potassium Channels - genetics</subject><subject>Potassium Channels - metabolism</subject><subject>Protein Conformation</subject><subject>Recombinant Proteins - chemistry</subject><subject>Recombinant Proteins - genetics</subject><subject>Recombinant Proteins - metabolism</subject><subject>selectivity filter</subject><subject>solid-state NMR</subject><subject>Spectrum Analysis</subject><subject>Streptomyces lividans - genetics</subject><subject>Streptomyces lividans - metabolism</subject><subject>Water - chemistry</subject><issn>0022-2836</issn><issn>1089-8638</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2010</creationdate><recordtype>article</recordtype><sourceid>EIF</sourceid><recordid>eNp9kU1v1DAQhi1ERZfCD-CCfOOUZWwnjiMkpGqhH2olEB9ny3HG1KskXmzvSvvv8bKlai-cLNvvPDOah5A3DJYMmHy_Xq6nfsmh3EEuQbBnZMFAdZWSQj0nCwDOK66EPCUvU1oDQCNq9YKccpAAjIsFGVZhdiFOJvswm5F-2s9m8jZRP9N8h_Q7jmiz3_m8pxd-zBhpcPTGpvND4humTZgT0hzo15BNSn470esw04K1OOf4l_uKnDgzJnx9f56Rnxeff6yuqtsvl9er89vKNkzmqhmYA-R93Q-SMck619dSddb0vINauLZH2ZQnMNg03KB1VhlUrXLWIHRKnJGPR-5m2084HAcY9Sb6ycS9Dsbrpz-zv9O_wk7zTrSsbQvg3T0ght9bTFlPPlkcRzNj2Cbd1qqTshV1SbJj0saQUkT30IWBPsjRa13k6IMcDVIXOaXm7ePxHir-2SiBD8cAliXtPEadrMeyyMHHYkEPwf8H_wc57aJY</recordid><startdate>20100813</startdate><enddate>20100813</enddate><creator>Bhate, Manasi P.</creator><creator>Wylie, Benjamin J.</creator><creator>Tian, Lin</creator><creator>McDermott, Ann E.</creator><general>Elsevier Ltd</general><scope>CGR</scope><scope>CUY</scope><scope>CVF</scope><scope>ECM</scope><scope>EIF</scope><scope>NPM</scope><scope>AAYXX</scope><scope>CITATION</scope><scope>7X8</scope><scope>5PM</scope></search><sort><creationdate>20100813</creationdate><title>Conformational Dynamics in the Selectivity Filter of KcsA in Response to Potassium Ion Concentration</title><author>Bhate, Manasi P. ; Wylie, Benjamin J. ; Tian, Lin ; McDermott, Ann E.</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-c516t-5d1f0e2b4bd611619fb4689cab29043f7be65b460ae552aecfc8ae878fcae0983</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>2010</creationdate><topic>Bacterial Proteins - chemistry</topic><topic>Bacterial Proteins - genetics</topic><topic>Bacterial Proteins - metabolism</topic><topic>Binding Sites</topic><topic>conformational dynamics</topic><topic>KcsA</topic><topic>Kinetics</topic><topic>Models, Molecular</topic><topic>Molecular Dynamics Simulation</topic><topic>Nuclear Magnetic Resonance, Biomolecular</topic><topic>Potassium - metabolism</topic><topic>potassium channel</topic><topic>Potassium Channels - chemistry</topic><topic>Potassium Channels - genetics</topic><topic>Potassium Channels - metabolism</topic><topic>Protein Conformation</topic><topic>Recombinant Proteins - chemistry</topic><topic>Recombinant Proteins - genetics</topic><topic>Recombinant Proteins - metabolism</topic><topic>selectivity filter</topic><topic>solid-state NMR</topic><topic>Spectrum Analysis</topic><topic>Streptomyces lividans - genetics</topic><topic>Streptomyces lividans - metabolism</topic><topic>Water - chemistry</topic><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Bhate, Manasi P.</creatorcontrib><creatorcontrib>Wylie, Benjamin J.</creatorcontrib><creatorcontrib>Tian, Lin</creatorcontrib><creatorcontrib>McDermott, Ann E.</creatorcontrib><collection>Medline</collection><collection>MEDLINE</collection><collection>MEDLINE (Ovid)</collection><collection>MEDLINE</collection><collection>MEDLINE</collection><collection>PubMed</collection><collection>CrossRef</collection><collection>MEDLINE - Academic</collection><collection>PubMed Central (Full Participant titles)</collection><jtitle>Journal of molecular biology</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>Bhate, Manasi P.</au><au>Wylie, Benjamin J.</au><au>Tian, Lin</au><au>McDermott, Ann E.</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Conformational Dynamics in the Selectivity Filter of KcsA in Response to Potassium Ion Concentration</atitle><jtitle>Journal of molecular biology</jtitle><addtitle>J Mol Biol</addtitle><date>2010-08-13</date><risdate>2010</risdate><volume>401</volume><issue>2</issue><spage>155</spage><epage>166</epage><pages>155-166</pages><issn>0022-2836</issn><eissn>1089-8638</eissn><abstract>Conformational change in the selectivity filter of KcsA as a function of ambient potassium concentration is studied with solid-state NMR. This highly conserved region of the protein is known to chelate potassium ions selectively. We report solid-state NMR chemical shift fingerprints of two distinct conformations of the selectivity filter; significant changes are observed in the chemical shifts of key residues in the filter as the potassium ion concentration is changed from 50 mM to 1 μM. Potassium ion titration studies reveal that the site-specific Kd for K+ binding at the key pore residue Val76 is on the order of ∼7 μM and that a relatively high sample hydration is necessary to observe the low-K+ conformer. Simultaneous detection of both conformers at low ambient potassium concentration suggests that the high-K+ and low-K+ states are in slow exchange on the NMR timescale (kex<500 s−1). The slow rate and tight binding for evacuating both inner sites simultaneously differ from prior observations in detergent in solution, but agree well with measurements by electrophysiology and appear to result from our use of a hydrated bilayer environment. These observations strongly support a common assumption that the low-K+ state is not involved in ion transmission, and that during transmission one of the two inner sites is always occupied. On the other hand, these kinetic and thermodynamic characteristics of the evacuation of the inner sites certainly could be compatible with participation in a control mechanism at low ion concentration such as C-type inactivation, a process that is coupled to activation and involves closing of the outer mouth of the channel.</abstract><cop>Netherlands</cop><pub>Elsevier Ltd</pub><pmid>20600123</pmid><doi>10.1016/j.jmb.2010.06.031</doi><tpages>12</tpages><oa>free_for_read</oa></addata></record> |
| fulltext | fulltext |
| identifier | ISSN: 0022-2836 |
| ispartof | Journal of molecular biology, 2010-08, Vol.401 (2), p.155-166 |
| issn | 0022-2836 1089-8638 |
| language | eng |
| recordid | cdi_pubmedcentral_primary_oai_pubmedcentral_nih_gov_2937177 |
| source | MEDLINE; Elsevier ScienceDirect Journals Complete |
| subjects | Bacterial Proteins - chemistry Bacterial Proteins - genetics Bacterial Proteins - metabolism Binding Sites conformational dynamics KcsA Kinetics Models, Molecular Molecular Dynamics Simulation Nuclear Magnetic Resonance, Biomolecular Potassium - metabolism potassium channel Potassium Channels - chemistry Potassium Channels - genetics Potassium Channels - metabolism Protein Conformation Recombinant Proteins - chemistry Recombinant Proteins - genetics Recombinant Proteins - metabolism selectivity filter solid-state NMR Spectrum Analysis Streptomyces lividans - genetics Streptomyces lividans - metabolism Water - chemistry |
| title | Conformational Dynamics in the Selectivity Filter of KcsA in Response to Potassium Ion Concentration |
| url | https://sfx.bib-bvb.de/sfx_tum?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2025-02-14T19%3A34%3A12IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-proquest_pubme&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Conformational%20Dynamics%20in%20the%20Selectivity%20Filter%20of%20KcsA%20in%20Response%20to%20Potassium%20Ion%20Concentration&rft.jtitle=Journal%20of%20molecular%20biology&rft.au=Bhate,%20Manasi%20P.&rft.date=2010-08-13&rft.volume=401&rft.issue=2&rft.spage=155&rft.epage=166&rft.pages=155-166&rft.issn=0022-2836&rft.eissn=1089-8638&rft_id=info:doi/10.1016/j.jmb.2010.06.031&rft_dat=%3Cproquest_pubme%3E748966734%3C/proquest_pubme%3E%3Curl%3E%3C/url%3E&disable_directlink=true&sfx.directlink=off&sfx.report_link=0&rft_id=info:oai/&rft_pqid=748966734&rft_id=info:pmid/20600123&rft_els_id=S0022283610006479&rfr_iscdi=true |