+Open data
-Basic information
Entry | Database: PDB / ID: 7e7i | ||||||
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Title | Cryo-EM structure of human ABCA4 in the apo state | ||||||
Components | Retinal-specific phospholipid-transporting ATPase ABCA4 | ||||||
Keywords | TRANSLOCASE / lipid transport / MEMBRANE PROTEIN | ||||||
Function / homology | Function and homology information rod photoreceptor disc membrane / flippase activity / N-retinylidene-phosphatidylethanolamine flippase activity / all-trans retinal binding / phospholipid transfer to membrane / retinol transmembrane transporter activity / phospholipid transporter activity / 11-cis retinal binding / ATPase-coupled intramembrane lipid transporter activity / retinal metabolic process ...rod photoreceptor disc membrane / flippase activity / N-retinylidene-phosphatidylethanolamine flippase activity / all-trans retinal binding / phospholipid transfer to membrane / retinol transmembrane transporter activity / phospholipid transporter activity / 11-cis retinal binding / ATPase-coupled intramembrane lipid transporter activity / retinal metabolic process / phosphatidylethanolamine flippase activity / phototransduction, visible light / retinoid binding / P-type phospholipid transporter / photoreceptor cell maintenance / phospholipid translocation / retinoid metabolic process / lipid transport / Retinoid cycle disease events / The canonical retinoid cycle in rods (twilight vision) / ATPase-coupled transmembrane transporter activity / photoreceptor outer segment / ABC-type transporter activity / visual perception / ABC-family proteins mediated transport / transmembrane transport / photoreceptor disc membrane / cytoplasmic vesicle / intracellular membrane-bounded organelle / GTPase activity / endoplasmic reticulum / ATP hydrolysis activity / ATP binding / membrane / plasma membrane Similarity search - Function | ||||||
Biological species | Homo sapiens (human) | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.3 Å | ||||||
Authors | Xie, T. / Zhang, Z.K. / Gong, X. | ||||||
Citation | Journal: Nat Commun / Year: 2021 Title: Structural basis of substrate recognition and translocation by human ABCA4. Authors: Tian Xie / Zike Zhang / Qi Fang / Bowen Du / Xin Gong / Abstract: Human ATP-binding cassette (ABC) subfamily A (ABCA) transporters mediate the transport of various lipid compounds across the membrane. Mutations in human ABCA transporters have been described to ...Human ATP-binding cassette (ABC) subfamily A (ABCA) transporters mediate the transport of various lipid compounds across the membrane. Mutations in human ABCA transporters have been described to cause severe hereditary disorders associated with impaired lipid transport. However, little is known about the mechanistic details of substrate recognition and translocation by ABCA transporters. Here, we present three cryo-EM structures of human ABCA4, a retina-specific ABCA transporter, in distinct functional states at resolutions of 3.3-3.4 Å. In the nucleotide-free state, the two transmembrane domains (TMDs) exhibit a lateral-opening conformation, allowing the lateral entry of substrate from the lipid bilayer. The N-retinylidene-phosphatidylethanolamine (NRPE), the physiological lipid substrate of ABCA4, is sandwiched between the two TMDs in the luminal leaflet and is further stabilized by an extended loop from extracellular domain 1. In the ATP-bound state, the two TMDs display a closed conformation, which precludes the substrate binding. Our study provides a molecular basis to understand the mechanism of ABCA4-mediated NRPE recognition and translocation, and suggests a common 'lateral access and extrusion' mechanism for ABCA-mediated lipid transport. | ||||||
History |
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-Structure visualization
Movie |
Movie viewer |
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Structure viewer | Molecule: MolmilJmol/JSmol |
-Downloads & links
-Download
PDBx/mmCIF format | 7e7i.cif.gz | 378.7 KB | Display | PDBx/mmCIF format |
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PDB format | pdb7e7i.ent.gz | 291.8 KB | Display | PDB format |
PDBx/mmJSON format | 7e7i.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Summary document | 7e7i_validation.pdf.gz | 1.1 MB | Display | wwPDB validaton report |
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Full document | 7e7i_full_validation.pdf.gz | 1.2 MB | Display | |
Data in XML | 7e7i_validation.xml.gz | 60.9 KB | Display | |
Data in CIF | 7e7i_validation.cif.gz | 90.6 KB | Display | |
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/e7/7e7i ftp://data.pdbj.org/pub/pdb/validation_reports/e7/7e7i | HTTPS FTP |
-Related structure data
Related structure data | 31000MC 7e7oC 7e7qC M: map data used to model this data C: citing same article (ref.) |
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Similar structure data |
-Links
-Assembly
Deposited unit |
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1 |
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-Components
#1: Protein | Mass: 261143.547 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Homo sapiens (human) / Gene: ABCA4, ABCR / Production host: Homo sapiens (human) References: UniProt: P78363, P-type phospholipid transporter | ||||||||
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#2: Polysaccharide | Source method: isolated from a genetically manipulated source #3: Sugar | ChemComp-NAG / #4: Chemical | Has ligand of interest | Y | 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: ABCA4 / Type: COMPLEX / Entity ID: #1 / Source: RECOMBINANT |
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Source (natural) | Organism: Homo sapiens (human) |
Source (recombinant) | Organism: Homo sapiens (human) |
Buffer solution | pH: 7.5 |
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 |
Image recording | Electron dose: 50 e/Å2 / Film or detector model: GATAN K2 SUMMIT (4k x 4k) |
-Processing
Software | Name: PHENIX / Version: 1.18.1_3865: / Classification: refinement | ||||||||||||||||||||||||
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CTF correction | Type: NONE | ||||||||||||||||||||||||
3D reconstruction | Resolution: 3.3 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 205597 / Symmetry type: POINT | ||||||||||||||||||||||||
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