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Open data
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Basic information
Entry | Database: PDB / ID: 7e7q | ||||||
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Title | Cryo-EM structure of human ABCA4 in ATP-bound state | ||||||
![]() | Retinal-specific phospholipid-transporting ATPase ABCA4 | ||||||
![]() | TRANSLOCASE / lipid transport / MEMBRANE PROTEIN | ||||||
Function / homology | ![]() 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 / retinal metabolic process / ATPase-coupled intramembrane lipid transporter activity ...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 / retinal metabolic process / ATPase-coupled intramembrane lipid transporter activity / phosphatidylethanolamine flippase activity / phototransduction, visible light / retinoid binding / photoreceptor cell maintenance / P-type phospholipid transporter / phospholipid translocation / lipid transport / retinoid metabolic process / Retinoid cycle disease events / The canonical retinoid cycle in rods (twilight vision) / photoreceptor outer segment / ATPase-coupled transmembrane transporter activity / 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 | ![]() | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.3 Å | ||||||
![]() | Xie, T. / Zhang, Z.K. / Gong, X. | ||||||
![]() | ![]() 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. | ||||||
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Structure visualization
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Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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PDBx/mmCIF format | ![]() | 363 KB | Display | ![]() |
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PDB format | ![]() | 288.7 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Arichive directory | ![]() ![]() | HTTPS FTP |
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-Related structure data
Related structure data | ![]() 31002MC ![]() 7e7iC ![]() 7e7oC C: citing same article ( M: map data used to model this data |
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Similar structure data |
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Links
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Assembly
Deposited unit | ![]()
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Components
#1: Protein | Mass: 261141.578 Da / Num. of mol.: 1 / Mutation: E1087Q,E2096Q Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() 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 | #5: Chemical | Has ligand of interest | Y | |
-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: ATP-bound ABCA4 / Type: COMPLEX / Entity ID: #1 / Source: RECOMBINANT |
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Source (natural) | Organism: ![]() |
Source (recombinant) | Organism: ![]() |
Buffer solution | pH: 7.5 |
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
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 |
Image recording | Electron dose: 50 e/Å2 / Film or detector model: GATAN K2 SUMMIT (4k x 4k) |
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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: 173278 / Symmetry type: POINT | ||||||||||||||||||||||||
Refine LS restraints |
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