+Open data
-Basic information
Entry | Database: PDB / ID: 8dwi | ||||||||||||
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Title | Molecular Mechanism of Sialic Acid Transport Mediated by Sialin | ||||||||||||
Components | Sialin | ||||||||||||
Keywords | MEMBRANE PROTEIN / sialic acid transport / solute carrier transporter | ||||||||||||
Function / homology | Function and homology information sialic acid:proton symporter activity / sialic acid transport / D-glucuronate transmembrane transporter activity / Defective SLC17A5 causes Salla disease (SD) and ISSD / Organic anion transporters / sialic acid transmembrane transporter activity / carbohydrate:proton symporter activity / Sialic acid metabolism / amino acid transport / monoatomic anion transport ...sialic acid:proton symporter activity / sialic acid transport / D-glucuronate transmembrane transporter activity / Defective SLC17A5 causes Salla disease (SD) and ISSD / Organic anion transporters / sialic acid transmembrane transporter activity / carbohydrate:proton symporter activity / Sialic acid metabolism / amino acid transport / monoatomic anion transport / transmembrane transporter activity / monoatomic ion transport / response to bacterium / synaptic vesicle membrane / lysosome / lysosomal membrane / membrane / plasma membrane / cytosol Similarity search - Function | ||||||||||||
Biological species | Homo sapiens (human) | ||||||||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.4 Å | ||||||||||||
Authors | Hu, W. / Zheng, H. | ||||||||||||
Funding support | United States, 3items
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Citation | Journal: Sci Adv / Year: 2023 Title: The molecular mechanism of sialic acid transport mediated by Sialin. Authors: Wenxin Hu / Congwu Chi / Kunhua Song / Hongjin Zheng / Abstract: Malfunction of the sialic acid transporter caused by various genetic mutations in the gene encoding Sialin leads to a spectrum of neurodegenerative conditions called free sialic acid storage ...Malfunction of the sialic acid transporter caused by various genetic mutations in the gene encoding Sialin leads to a spectrum of neurodegenerative conditions called free sialic acid storage disorders. Unfortunately, how Sialin transports sialic acid/proton (H) and how pathogenic mutations impair its function are poorly defined. Here, we present the structure of human Sialin in an inward-facing partially open conformation determined by cryo-electron microscopy, representing the first high-resolution structure of any human SLC17 member. Our analysis reveals two unique features in Sialin: (i) The H coupling/sensing requires two highly conserved Glu residues (E171 and E175) instead of one (E175) as implied in previous studies; and (ii) the normal function of Sialin requires the stabilization of a cytosolic helix, which has not been noticed in the literature. By mapping known pathogenic mutations, we provide mechanistic explanations for corresponding functional defects. We propose a structure-based mechanism for sialic acid transport mediated by Sialin. | ||||||||||||
History |
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-Structure visualization
Structure viewer | Molecule: MolmilJmol/JSmol |
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-Downloads & links
-Download
PDBx/mmCIF format | 8dwi.cif.gz | 80.1 KB | Display | PDBx/mmCIF format |
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PDB format | pdb8dwi.ent.gz | 60.6 KB | Display | PDB format |
PDBx/mmJSON format | 8dwi.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/dw/8dwi ftp://data.pdbj.org/pub/pdb/validation_reports/dw/8dwi | HTTPS FTP |
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-Related structure data
Related structure data | 27755MC 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
#1: Protein | Mass: 54684.168 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Homo sapiens (human) / Gene: SLC17A5 / Production host: Escherichia coli (E. coli) / References: UniProt: Q9NRA2 |
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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 |
-Sample preparation
Component | Name: Sialin complex with Fab 8B1 / Type: COMPLEX / Entity ID: all / Source: RECOMBINANT |
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Source (natural) | Organism: Homo sapiens (human) |
Source (recombinant) | Organism: Escherichia coli (E. coli) |
Buffer solution | pH: 7.4 |
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 FIELDBright-field microscopy / Nominal defocus max: 2500 nm / Nominal defocus min: 1000 nm |
Image recording | Electron dose: 57.2 e/Å2 / Film or detector model: GATAN K3 BIOQUANTUM (6k x 4k) |
-Processing
Software | Name: PHENIX / Version: 1.19.2_4158: / Classification: refinement | ||||||||||||||||||||||||
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
3D reconstruction | Resolution: 3.4 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 394078 / Symmetry type: POINT | ||||||||||||||||||||||||
Refine LS restraints |
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