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Open data
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Basic information
Entry | Database: PDB / ID: 8pxb | ||||||
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Title | Cryo-EM structure of horse NHE9 with a extracellular loop | ||||||
![]() | Sodium/hydrogen exchanger 9 | ||||||
![]() | TRANSPORT PROTEIN / Na+/H+ exchanger / membrane protein / SLC9A9 / ion transporter | ||||||
Function / homology | ![]() phagosome maturation / potassium:proton antiporter activity / sodium:proton antiporter activity / early phagosome / sodium ion import across plasma membrane / potassium ion transmembrane transport / sodium ion transmembrane transport / proton transmembrane transport / regulation of intracellular pH / recycling endosome ...phagosome maturation / potassium:proton antiporter activity / sodium:proton antiporter activity / early phagosome / sodium ion import across plasma membrane / potassium ion transmembrane transport / sodium ion transmembrane transport / proton transmembrane transport / regulation of intracellular pH / recycling endosome / recycling endosome membrane / phagocytic vesicle membrane / late endosome membrane / early endosome membrane / defense response to bacterium / protein homodimerization activity / plasma membrane Similarity search - Function | ||||||
Biological species | ![]() ![]() | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.6 Å | ||||||
![]() | Kokane, S. / Meier, P. / Matsuoka, R. / Drew, D. | ||||||
Funding support | European Union, 1items
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![]() | ![]() Title: PIP-mediated oligomerization of the endosomal sodium/proton exchanger NHE9. Authors: Surabhi Kokane / Ashutosh Gulati / Pascal F Meier / Rei Matsuoka / Tanadet Pipatpolkai / Giuseppe Albano / Tin Manh Ho / Lucie Delemotte / Daniel Fuster / David Drew / ![]() ![]() Abstract: The strict exchange of Na for H ions across cell membranes is a reaction carried out in almost every cell. Na/H exchangers that perform this task are physiological homodimers, and whilst the ion ...The strict exchange of Na for H ions across cell membranes is a reaction carried out in almost every cell. Na/H exchangers that perform this task are physiological homodimers, and whilst the ion transporting domain is highly conserved, their dimerization differs. The Na/H exchanger NhaA from Escherichia coli has a weak dimerization interface mediated by a β-hairpin domain and with dimer retention dependent on cardiolipin. Similarly, organellar Na/H exchangers NHE6, NHE7 and NHE9 also contain β-hairpin domains and recent analysis of Equus caballus NHE9 indicated PIP lipids could bind at the dimer interface. However, structural validation of the predicted lipid-mediated oligomerization has been lacking. Here, we report cryo-EM structures of E. coli NhaA and E. caballus NHE9 in complex with cardiolipin and phosphatidylinositol-3,5-bisphosphate PI(3,5)P lipids binding at their respective dimer interfaces. We further show how the endosomal specific PI(3,5)P lipid stabilizes the NHE9 homodimer and enhances transport activity. Indeed, we show that NHE9 is active in endosomes, but not at the plasma membrane where the PI(3,5)P lipid is absent. Thus, specific lipids can regulate Na/H exchange activity by stabilizing dimerization in response to either cell specific cues or upon trafficking to their correct membrane location. | ||||||
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Structure visualization
Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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Download
PDBx/mmCIF format | ![]() | 186.1 KB | Display | ![]() |
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PDB format | ![]() | 147.2 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Summary document | ![]() | 1.3 MB | Display | ![]() |
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Full document | ![]() | 1.3 MB | Display | |
Data in XML | ![]() | 37.5 KB | Display | |
Data in CIF | ![]() | 53.9 KB | Display | |
Arichive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 18002MC ![]() 8pvrC M: map data used to model this data C: citing same article ( |
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Similar structure data | Similarity search - Function & homology ![]() |
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Links
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Assembly
Deposited unit | ![]()
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Components
#1: Protein | Mass: 64876.086 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() ![]() ![]() Has protein modification | N | |
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-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
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Sample preparation
Component | Name: Dimeric Horse Nhe9 / Type: COMPLEX / Entity ID: all / Source: RECOMBINANT |
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Source (natural) | Organism: ![]() ![]() |
Source (recombinant) | Organism: ![]() ![]() |
Buffer solution | pH: 6.5 |
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Specimen support | Grid material: COPPER / Grid mesh size: 300 divisions/in. / Grid type: Quantifoil R2/1 |
Vitrification | Cryogen name: ETHANE |
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Electron microscopy imaging
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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Microscopy | Model: FEI TITAN KRIOS |
Electron gun | Electron source: ![]() |
Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 2000 nm / Nominal defocus min: 600 nm |
Image recording | Electron dose: 80 e/Å2 / Film or detector model: GATAN K2 IS (4k x 4k) |
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Processing
CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
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3D reconstruction | Resolution: 3.6 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 103815 / Symmetry type: POINT | ||||||||||||||||||||||||
Refine LS restraints |
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