+Open data
-Basic information
Entry | Database: PDB / ID: 8k69 | ||||||
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Title | Cryo-EM structure of Oryza sativa HKT2;2/1 at 2.3 angstrom | ||||||
Components | Cation transporter HKT2;2 | ||||||
Keywords | TRANSPORT PROTEIN / HKT / K+ transporter / Channel | ||||||
Function / homology | Function and homology information monoatomic cation transmembrane transporter activity / sodium ion transport / potassium ion transport / membrane Similarity search - Function | ||||||
Biological species | Oryza sativa subsp. indica (long-grained rice) | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.33 Å | ||||||
Authors | Wang, X. / Shen, X. / Qu, Y. / Wang, C. / Shen, H. | ||||||
Funding support | China, 1items
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Citation | Journal: Nat Plants / Year: 2024 Title: Structural insights into ion selectivity and transport mechanisms of Oryza sativa HKT2;1 and HKT2;2/1 transporters. Authors: Xiaohui Wang / Xiaoshuai Shen / Yannan Qu / Heng Zhang / Chu Wang / Fan Yang / Huaizong Shen / Abstract: Plant high-affinity K transporters (HKTs) play a pivotal role in maintaining the balance of Na and K ions in plants, thereby influencing plant growth under K-depleted conditions and enhancing ...Plant high-affinity K transporters (HKTs) play a pivotal role in maintaining the balance of Na and K ions in plants, thereby influencing plant growth under K-depleted conditions and enhancing tolerance to salinity stress. Here we report the cryo-electron microscopy structures of Oryza sativa HKT2;1 and HKT2;2/1 at overall resolutions of 2.5 Å and 2.3 Å, respectively. Both transporters adopt a dimeric assembly, with each protomer enclosing an ion permeation pathway. Comparison between the selectivity filters of the two transporters reveals the critical roles of Ser88/Gly88 and Val243/Gly243 in determining ion selectivity. A constriction site along the ion permeation pathway is identified, consisting of Glu114, Asn273, Pro392, Pro393, Arg525, Lys517 and the carboxy-terminal Trp530 from the neighbouring protomer. The linker between domains II and III adopts a stable loop structure oriented towards the constriction site, potentially participating in the gating process. Electrophysiological recordings, yeast complementation assays and molecular dynamics simulations corroborate the functional importance of these structural features. Our findings provide crucial insights into the ion selectivity and transport mechanisms of plant HKTs, offering valuable structural templates for developing new salinity-tolerant cultivars and strategies to increase crop yields. | ||||||
History |
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-Structure visualization
Structure viewer | Molecule: MolmilJmol/JSmol |
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-Downloads & links
-Download
PDBx/mmCIF format | 8k69.cif.gz | 190 KB | Display | PDBx/mmCIF format |
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PDB format | pdb8k69.ent.gz | 145 KB | Display | PDB format |
PDBx/mmJSON format | 8k69.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Summary document | 8k69_validation.pdf.gz | 850.9 KB | Display | wwPDB validaton report |
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Full document | 8k69_full_validation.pdf.gz | 877.6 KB | Display | |
Data in XML | 8k69_validation.xml.gz | 25.2 KB | Display | |
Data in CIF | 8k69_validation.cif.gz | 34.1 KB | Display | |
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/k6/8k69 ftp://data.pdbj.org/pub/pdb/validation_reports/k6/8k69 | HTTPS FTP |
-Related structure data
Related structure data | 36919MC 8k66C M: map data used to model this data C: citing same article (ref.) |
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Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
-Assembly
Deposited unit |
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1 |
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-Components
-Protein , 1 types, 2 molecules AB
#1: Protein | Mass: 60773.238 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Oryza sativa subsp. indica (long-grained rice) Gene: HKT2;2, HKT2 / Production host: Homo sapiens (human) / References: UniProt: Q93XI5 |
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-Non-polymers , 7 types, 144 molecules
#2: Chemical | ChemComp-Y01 / #3: Chemical | #4: Chemical | #5: Chemical | #6: Chemical | #7: Chemical | ChemComp-NA / #8: Water | ChemComp-HOH / | |
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-Details
Has ligand of interest | N |
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Has protein modification | Y |
-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
-Sample preparation
Component | Name: OsHKT2;2/1 dimer / Type: COMPLEX / Entity ID: #1 / Source: RECOMBINANT |
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Source (natural) | Organism: Oryza sativa subsp. indica (long-grained rice) |
Source (recombinant) | Organism: Homo sapiens (human) |
Buffer solution | pH: 7 |
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Vitrification | Cryogen name: ETHANE |
-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: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM |
Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 2200 nm / Nominal defocus min: 1200 nm |
Image recording | Electron dose: 50 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) |
-Processing
CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
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3D reconstruction | Resolution: 2.33 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 639952 / Symmetry type: POINT | ||||||||||||||||||||||||
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