4WJK

Metal Ion and Ligand Binding of Integrin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.238 
  • R-Value Work: 0.191 

wwPDB Validation 3D Report Full Report


This is version 2.0 of the entry. See complete history

Literature

Metal ion and ligand binding of integrin alpha 5 beta 1.

Xia, W.Springer, T.A.

(2014) Proc.Natl.Acad.Sci.USA 111: 17863-17868

  • DOI: 10.1073/pnas.1420645111
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Integrin α5β1 binds to an Arg-Gly-Asp (RGD) motif in its ligand fibronectin. We report high-resolution crystal structures of a four-domain α5β1 headpiece fragment, alone or with RGD peptides soaked into crystals, and RGD peptide affinity measurements ...

    Integrin α5β1 binds to an Arg-Gly-Asp (RGD) motif in its ligand fibronectin. We report high-resolution crystal structures of a four-domain α5β1 headpiece fragment, alone or with RGD peptides soaked into crystals, and RGD peptide affinity measurements. The headpiece crystallizes in a closed conformation essentially identical to that seen previously for α5β1 complexed with a Fab that allosterically inhibits ligand binding by stabilizing the closed conformation. Soaking experiments show that binding of cyclic RGD peptide with 20-fold higher affinity than a linear RGD peptide induces conformational change in the β1-subunit βI domain to a state that is intermediate between closed (low affinity) and open (high affinity). In contrast, binding of a linear RGD peptide induces no shape shifting. However, linear peptide binding induces shape shifting when Ca(2+) is depleted during soaking. Ca(2+) bound to the adjacent to metal ion-dependent adhesion site (ADMIDAS), at the locus of shape shifting, moves and decreases in occupancy, correlating with an increase in affinity for RGD measured when Ca(2+) is depleted. The results directly demonstrate that Ca(2+) binding to the ADMIDAS stabilizes integrins in the low-affinity, closed conformation. Comparisons in affinity between four-domain and six-domain headpiece constructs suggest that flexible integrin leg domains contribute to conformational equilibria. High-resolution views of the hybrid domain interface with the plexin-semaphorin-integrin (PSI) domain in different orientations show a ball-and-socket joint with a hybrid domain Arg side chain that rocks in a PSI domain socket lined with carbonyl oxygens.


    Organizational Affiliation

    Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115; and Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Integrin alpha-5
A
452Homo sapiensMutation(s): 1 
Gene Names: ITGA5 (FNRA)
Find proteins for P08648 (Homo sapiens)
Go to Gene View: ITGA5
Go to UniProtKB:  P08648
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Integrin beta-1
B
445Homo sapiensMutation(s): 0 
Gene Names: ITGB1 (FNRB, MDF2, MSK12)
Find proteins for P05556 (Homo sapiens)
Go to Gene View: ITGB1
Go to UniProtKB:  P05556
Small Molecules
Ligands 5 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
A, B
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
MAN
Query on MAN

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Download CCD File 
A, B
ALPHA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-PQMKYFCFSA-N
 Ligand Interaction
BMA
Query on BMA

Download SDF File 
Download CCD File 
A, B
BETA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-RWOPYEJCSA-N
 Ligand Interaction
MG
Query on MG

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Download CCD File 
B
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
NAG
Query on NAG

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Download CCD File 
A, B
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.238 
  • R-Value Work: 0.191 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 52.130α = 90.00
b = 116.750β = 90.00
c = 159.490γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata scaling
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-12-03
    Type: Initial release
  • Version 1.1: 2014-12-17
    Type: Database references
  • Version 1.2: 2014-12-24
    Type: Database references
  • Version 2.0: 2017-11-22
    Type: Atomic model, Database references, Derived calculations, Other, Refinement description, Source and taxonomy, Structure summary