+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-16319 | |||||||||
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Title | Structure of the K+/H+ exchanger KefC with GSH | |||||||||
Map data | ||||||||||
Sample |
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Keywords | potassium proton exchanger / KefC / Transporter / CPA / MEMBRANE PROTEIN / GSH | |||||||||
Function / homology | Function and homology information glutathione-regulated potassium exporter activity / response to methylglyoxal / antiporter activity / toxic substance binding / proton transmembrane transport / enzyme binding / plasma membrane Similarity search - Function | |||||||||
Biological species | Escherichia coli (E. coli) | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 3.18 Å | |||||||||
Authors | Gulati A / Drew D | |||||||||
Funding support | European Union, Sweden, 2 items
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Citation | Journal: Nat Commun / Year: 2024 Title: Structure and mechanism of the K/H exchanger KefC. Authors: Ashutosh Gulati / Surabhi Kokane / Annemarie Perez-Boerema / Claudia Alleva / Pascal F Meier / Rei Matsuoka / David Drew / Abstract: Intracellular potassium (K) homeostasis is fundamental to cell viability. In addition to channels, K levels are maintained by various ion transporters. One major family is the proton-driven K efflux ...Intracellular potassium (K) homeostasis is fundamental to cell viability. In addition to channels, K levels are maintained by various ion transporters. One major family is the proton-driven K efflux transporters, which in gram-negative bacteria is important for detoxification and in plants is critical for efficient photosynthesis and growth. Despite their importance, the structure and molecular basis for K-selectivity is poorly understood. Here, we report ~3.1 Å resolution cryo-EM structures of the Escherichia coli glutathione (GSH)-gated K efflux transporter KefC in complex with AMP, AMP/GSH and an ion-binding variant. KefC forms a homodimer similar to the inward-facing conformation of Na/H antiporter NapA. By structural assignment of a coordinated K ion, MD simulations, and SSM-based electrophysiology, we demonstrate how ion-binding in KefC is adapted for binding a dehydrated K ion. KefC harbors C-terminal regulator of K conductance (RCK) domains, as present in some bacterial K-ion channels. The domain-swapped helices in the RCK domains bind AMP and GSH and they inhibit transport by directly interacting with the ion-transporter module. Taken together, we propose that KefC is activated by detachment of the RCK domains and that ion selectivity exploits the biophysical properties likewise adapted by K-ion-channels. | |||||||||
History |
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-Structure visualization
Supplemental images |
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-Downloads & links
-EMDB archive
Map data | emd_16319.map.gz | 95.3 MB | EMDB map data format | |
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Header (meta data) | emd-16319-v30.xml emd-16319.xml | 15.4 KB 15.4 KB | Display Display | EMDB header |
FSC (resolution estimation) | emd_16319_fsc.xml | 9.9 KB | Display | FSC data file |
Images | emd_16319.png | 96.1 KB | ||
Filedesc metadata | emd-16319.cif.gz | 6.9 KB | ||
Others | emd_16319_half_map_1.map.gz emd_16319_half_map_2.map.gz | 95.5 MB 95.5 MB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-16319 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-16319 | HTTPS FTP |
-Validation report
Summary document | emd_16319_validation.pdf.gz | 1.1 MB | Display | EMDB validaton report |
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Full document | emd_16319_full_validation.pdf.gz | 1.1 MB | Display | |
Data in XML | emd_16319_validation.xml.gz | 18.3 KB | Display | |
Data in CIF | emd_16319_validation.cif.gz | 23.5 KB | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-16319 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-16319 | HTTPS FTP |
-Related structure data
Related structure data | 8by2MC 8bxgC M: atomic model generated by this map C: citing same article (ref.) |
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Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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Related items in Molecule of the Month |
-Map
File | Download / File: emd_16319.map.gz / Format: CCP4 / Size: 103 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||
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Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 0.886 Å | ||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
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-Supplemental data
-Half map: #2
File | emd_16319_half_map_1.map | ||||||||||||
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Projections & Slices |
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Density Histograms |
-Half map: #1
File | emd_16319_half_map_2.map | ||||||||||||
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Projections & Slices |
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Density Histograms |
-Sample components
-Entire : Kefc protein dimer with GSH
Entire | Name: Kefc protein dimer with GSH |
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Components |
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-Supramolecule #1: Kefc protein dimer with GSH
Supramolecule | Name: Kefc protein dimer with GSH / type: complex / ID: 1 / Parent: 0 / Macromolecule list: #1 |
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Source (natural) | Organism: Escherichia coli (E. coli) |
-Macromolecule #1: Glutathione-regulated potassium-efflux system protein KefC
Macromolecule | Name: Glutathione-regulated potassium-efflux system protein KefC type: protein_or_peptide / ID: 1 / Number of copies: 2 / Enantiomer: LEVO |
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Source (natural) | Organism: Escherichia coli (E. coli) |
Molecular weight | Theoretical: 61.183223 KDa |
Recombinant expression | Organism: Escherichia coli (E. coli) |
Sequence | String: MDSHTLIQAL IYLGSAALIV PIAVRLGLGS VLGYLIAGCI IGPWGLRLVT DAESILHFAE IGVVLMLFII GLELDPQRLW KLRAAVFGG GALQMVICGG LLGLFCMLLG LRWQVAELIG MTLALSSTAI AMQAMNERNL MVTQMGRSAF AVLLFQDIAA I PLVAMIPL ...String: MDSHTLIQAL IYLGSAALIV PIAVRLGLGS VLGYLIAGCI IGPWGLRLVT DAESILHFAE IGVVLMLFII GLELDPQRLW KLRAAVFGG GALQMVICGG LLGLFCMLLG LRWQVAELIG MTLALSSTAI AMQAMNERNL MVTQMGRSAF AVLLFQDIAA I PLVAMIPL LATSSASTTM GAFALSALKV AGALVLVVLL GRYVTRPALR FVARSGLREV FSAVALFLVF GFGLLLEEVG LS MAMGAFL AGVLLASSEY RHALESDIEP FKGLLLGLFF IGVGMSIDFG TLLENPLRIV ILLLGFLIIK IAMLWLIARP LQV PNKQRR WFAVLLGQGS EFAFVVFGAA QMANVLEPEW AKSLTLAVAL SMAATPILLV ILNRLEQSST EEAREADEID EEQP RVIIA GFGRFGQITG RLLLSSGVKM VVLDHDPDHI ETLRKFGMKV FYGDATRMDL LESAGAAKAE VLINAIDDPQ TNLQL TEMV KEHFPHLQII ARARDVDHYI RLRQAGVEKP ERETFEGALK TGRLALESLG LGPYEARERA DVFRRFNIQM VEEMAM V UniProtKB: Glutathione-regulated potassium-efflux system protein KefC |
-Macromolecule #2: POTASSIUM ION
Macromolecule | Name: POTASSIUM ION / type: ligand / ID: 2 / Number of copies: 2 / Formula: K |
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Molecular weight | Theoretical: 39.098 Da |
-Macromolecule #3: ADENOSINE MONOPHOSPHATE
Macromolecule | Name: ADENOSINE MONOPHOSPHATE / type: ligand / ID: 3 / Number of copies: 2 / Formula: AMP |
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Molecular weight | Theoretical: 347.221 Da |
Chemical component information | ChemComp-AMP: |
-Macromolecule #4: GLUTATHIONE
Macromolecule | Name: GLUTATHIONE / type: ligand / ID: 4 / Number of copies: 2 / Formula: GSH |
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Molecular weight | Theoretical: 307.323 Da |
Chemical component information | ChemComp-GSH: |
-Macromolecule #5: (1R)-2-{[(S)-{[(2S)-2,3-dihydroxypropyl]oxy}(hydroxy)phosphoryl]o...
Macromolecule | Name: (1R)-2-{[(S)-{[(2S)-2,3-dihydroxypropyl]oxy}(hydroxy)phosphoryl]oxy}-1-[(hexadecanoyloxy)methyl]ethyl (9Z)-octadec-9-enoate type: ligand / ID: 5 / Number of copies: 2 / Formula: PGW |
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Molecular weight | Theoretical: 749.007 Da |
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Buffer | pH: 7.5 |
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Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Instrument: FEI VITROBOT MARK IV |
-Electron microscopy
Microscope | FEI TITAN KRIOS |
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Image recording | Film or detector model: GATAN K3 BIOQUANTUM (6k x 4k) / Average electron dose: 64.3 e/Å2 |
Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
Electron optics | C2 aperture diameter: 50.0 µm / Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Nominal defocus max: 2.0 µm / Nominal defocus min: 0.6 µm / Nominal magnification: 130000 |
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |