Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: gel filtration

Macromolecule Content

• Total Structure Weight: 268.28 kDa 
• Atom Count: 15,789 
• Modelled Residue Count: 1,941 
• Deposited Residue Count: 2,273 
• Unique protein chains: 1

 7LKP

Structure of ATP-free human ABCA4

• PDB DOI: 10.2210/pdb7LKP/pdb
• EM Map EMD-23409: EMDB EMDataResource

• Classification: TRANSLOCASE
• Organism(s): Homo sapiens
• Expression System: Homo sapiens
• Mutation(s): No 
• Membrane Protein: Yes  OPMPDBTMMemProtMDmpstruc


• Deposited: 2021-02-02 Released: 2021-03-03 
• Deposition Author(s): Liu, F., Lee, J., Chen, J.
• Funding Organization(s): Howard Hughes Medical Institute (HHMI)

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 3.27 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

Molecular structures of the eukaryotic retinal importer ABCA4.

Liu, F., Lee, J., Chen, J.

(2021) Elife 10

• PubMed: 33605212 
• DOI: 10.7554/eLife.63524
• Primary Citation of Related Structures:  
  7LKP, 7LKZ


• PubMed Abstract: 
  

The ATP-binding cassette (ABC) transporter family contains thousands of members with diverse functions. Movement of the substrate, powered by ATP hydrolysis, can be outward (export) or inward (import). ABCA4 is a eukaryotic importer transporting retinal to the cytosol to enter the visual cycle. It also removes toxic retinoids from the disc lumen. Mutations in ABCA4 cause impaired vision or blindness. Despite decades of clinical, biochemical, and animal model studies, the molecular mechanism of ABCA4 is unknown. Here, we report the structures of human ABCA4 in two conformations. In the absence of ATP, ABCA4 adopts an outward-facing conformation, poised to recruit substrate. The presence of ATP induces large conformational changes that could lead to substrate release. These structures provide a molecular basis to understand many disease-causing mutations and a rational guide for new experiments to uncover how ABCA4 recruits, flips, and releases retinoids.

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Organizational Affiliation: 

Howard Hughes Medical Institute, Chevy Chase, United States.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Retinal-specific phospholipid-transporting ATPase ABCA4	A	2,273	Homo sapiens	Mutation(s): 0  Gene Names: ABCA4, ABCR EC: 7.6.2.1 Membrane Entity: Yes
UniProt & NIH Common Fund Data Resources
Find proteins for P78363 (Homo sapiens) Explore P78363  Go to UniProtKB:  P78363
PHAROS:  P78363

Oligosaccharides

Help

Entity ID: 2
Molecule	Chains	Chain Length	2D Diagram	Glycosylation
beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose	B	3		N-Glycosylation
Glycosylation Resources
GlyTouCan:  G15407YE GlyCosmos:  G15407YE GlyGen:  G15407YE

Entity ID: 3
Molecule	Chains	Chain Length	2D Diagram	Glycosylation
beta-D-mannopyranose-(1-3)-[beta-D-mannopyranose-(1-6)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose	C	5		N-Glycosylation
Glycosylation Resources
GlyTouCan:  G89225LT GlyCosmos:  G89225LT GlyGen:  G89225LT

Small Molecules

Ligands 4 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
AJP	M [auth A]	Digitonin C56 H92 O29 UVYVLBIGDKGWPX-KUAJCENISA-N
POV	K [auth A], S [auth A], T [auth A], U [auth A], V [auth A], W [auth A], X [auth A]	(2S)-3-(hexadecanoyloxy)-2-[(9Z)-octadec-9-enoyloxy]propyl 2-(trimethylammonio)ethyl phosphate C42 H82 N O8 P WTJKGGKOPKCXLL-PFDVCBLKSA-N
CLR	J [auth A], L [auth A], N [auth A], O [auth A], P [auth A], Q [auth A], R [auth A]	CHOLESTEROL C27 H46 O HVYWMOMLDIMFJA-DPAQBDIFSA-N
NAG	D [auth A], E [auth A], F [auth A], G [auth A], H [auth A], I [auth A]	2-acetamido-2-deoxy-beta-D-glucopyranose C8 H15 N O6 OVRNDRQMDRJTHS-FMDGEEDCSA-N

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 3.27 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Structure Validation

Entry History & Funding Information

Deposition Data

• Released Date: 2021-03-03 
Deposition Author(s): Liu, F., Lee, J., Chen, J.

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Funding Organization	Location	Grant Number
Howard Hughes Medical Institute (HHMI)	United States	--

Revision History  

• Version 1.0: 2021-03-03
  Type: Initial release
  
• Version 2.0: 2021-08-25
  Changes: Advisory, Atomic model, Data collection, Database references