8T2U

Cryo-EM Structures of Full-length Integrin alphaIIbbeta3 in Native Lipids complexed with Eptifibatide

  • Classification: CELL ADHESION
  • Organism(s): Homo sapiens, synthetic construct
  • Mutation(s): No 
  • Membrane Protein: Yes  mpstruc

  • Deposited: 2023-06-06 Released: 2023-07-26 
  • Deposition Author(s): Adair, B., Xiong, J.P., Yeager, M., Arnaout, M.A.
  • Funding Organization(s): National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI), National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Disease (NIH/NIDDK), National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)

Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.10 Å
  • Aggregation State: CELL 
  • Reconstruction Method: SINGLE PARTICLE 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.0 of the entry. See complete history


Literature

Cryo-EM structures of full-length integrin alpha IIb beta 3 in native lipids.

Adair, B.D.Xiong, J.P.Yeager, M.Arnaout, M.A.

(2023) Nat Commun 14: 4168-4168

  • DOI: https://doi.org/10.1038/s41467-023-39763-0
  • Primary Citation of Related Structures:  
    8T2U, 8T2V

  • PubMed Abstract: 

    Platelet integrin αIIbβ3 is maintained in a bent inactive state (low affinity to physiologic ligand), but can rapidly switch to a ligand-competent (high-affinity) state in response to intracellular signals ("inside-out" activation). Once bound, ligands drive proadhesive "outside-in" signaling. Anti-αIIbβ3 drugs like eptifibatide can engage the inactive integrin directly, inhibiting thrombosis but inadvertently impairing αIIbβ3 hemostatic functions. Bidirectional αIIbβ3 signaling is mediated by reorganization of the associated αIIb and β3 transmembrane α-helices, but the underlying changes remain poorly defined absent the structure of the full-length receptor. We now report the cryo-EM structures of full-length αIIbβ3 in its apo and eptifibatide-bound states in native cell-membrane nanoparticles at near-atomic resolution. The apo form adopts the bent inactive state but with separated transmembrane α-helices, and a fully accessible ligand-binding site that challenges the model that this site is occluded by the plasma membrane. Bound eptifibatide triggers dramatic conformational changes that may account for impaired hemostasis. These results advance our understanding of integrin structure and function and may guide development of safer inhibitors.


  • Organizational Affiliation

    Leukocyte Biology and Inflammation Laboratory, Structural Biology Program, Division of Nephrology, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, 02114, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Integrin alpha-IIb1,008Homo sapiensMutation(s): 0 
Membrane Entity: Yes 
UniProt & NIH Common Fund Data Resources
Find proteins for P08514 (Homo sapiens)
Explore P08514 
Go to UniProtKB:  P08514
PHAROS:  P08514
GTEx:  ENSG00000005961 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP08514
Glycosylation
Glycosylation Sites: 2Go to GlyGen: P08514-1
Sequence Annotations
Expand
  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Integrin beta-3762Homo sapiensMutation(s): 0 
Membrane Entity: Yes 
UniProt & NIH Common Fund Data Resources
Find proteins for P05106 (Homo sapiens)
Explore P05106 
Go to UniProtKB:  P05106
PHAROS:  P05106
GTEx:  ENSG00000259207 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP05106
Glycosylation
Glycosylation Sites: 3Go to GlyGen: P05106-1
Sequence Annotations
Expand
  • Reference Sequence

Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
Eptifibatide8synthetic constructMutation(s): 0 
Sequence Annotations
Expand
  • Reference Sequence
Oligosaccharides

Help

Entity ID: 4
MoleculeChains Length2D Diagram Glycosylation3D Interactions
beta-D-mannopyranose-(1-4)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
D
4N-Glycosylation
Glycosylation Resources
GlyTouCan:  G53755TJ
GlyCosmos:  G53755TJ
GlyGen:  G53755TJ
Entity ID: 5
MoleculeChains Length2D Diagram Glycosylation3D Interactions
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
E
4N-Glycosylation
Glycosylation Resources
GlyTouCan:  G40894EI
GlyCosmos:  G40894EI
GlyGen:  G40894EI
Entity ID: 6
MoleculeChains Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
F
2N-Glycosylation
Glycosylation Resources
GlyTouCan:  G42666HT
GlyCosmos:  G42666HT
GlyGen:  G42666HT
Small Molecules
Ligands 3 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

Download Ideal Coordinates CCD File 
G [auth A],
O [auth B]
2-acetamido-2-deoxy-beta-D-glucopyranose
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
CA
Query on CA

Download Ideal Coordinates CCD File 
H [auth A]
I [auth A]
J [auth A]
K [auth A]
M [auth B]
H [auth A],
I [auth A],
J [auth A],
K [auth A],
M [auth B],
N [auth B]
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
MG
Query on MG

Download Ideal Coordinates CCD File 
L [auth B]MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
HRG
Query on HRG
C
L-PEPTIDE LINKINGC7 H16 N4 O2ARG
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.10 Å
  • Aggregation State: CELL 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion
RECONSTRUCTIONcryoSPARC4.2.1
MODEL REFINEMENTPHENIX1.20.1
MODEL REFINEMENTREFMAC5.8.0267

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)United StatesHL141366
National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Disease (NIH/NIDDK)United StatesDK088327
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM084545

Revision History  (Full details and data files)

  • Version 1.0: 2023-07-26
    Type: Initial release