3KRK

X-ray crystal structure of arachidonic acid bound in the cyclooxygenase channel of L531F murine COX-2


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.179 
  • R-Value Observed: 0.182 

Starting Model: experimental
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Ligand Structure Quality Assessment 


This is version 2.3 of the entry. See complete history


Literature

Structural basis of fatty acid substrate binding to cyclooxygenase-2.

Vecchio, A.J.Simmons, D.M.Malkowski, M.G.

(2010) J Biol Chem 285: 22152-22163

  • DOI: https://doi.org/10.1074/jbc.M110.119867
  • Primary Citation of Related Structures:  
    3HS5, 3HS6, 3HS7, 3KRK

  • PubMed Abstract: 

    The cyclooxygenases (COX-1 and COX-2) are membrane-associated heme-containing homodimers that generate prostaglandin H(2) from arachidonic acid (AA). Although AA is the preferred substrate, other fatty acids are oxygenated by these enzymes with varying efficiencies. We determined the crystal structures of AA, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) bound to Co(3+)-protoporphyrin IX-reconstituted murine COX-2 to 2.1, 2.4, and 2.65 A, respectively. AA, EPA, and docosahexaenoic acid bind in different conformations in each monomer constituting the homodimer in their respective structures such that one monomer exhibits nonproductive binding and the other productive binding of the substrate in the cyclooxygenase channel. The interactions identified between protein and substrate when bound to COX-1 are conserved in our COX-2 structures, with the only notable difference being the lack of interaction of the carboxylate of AA and EPA with the side chain of Arg-120. Leu-531 exhibits a different side chain conformation when the nonproductive and productive binding modes of AA are compared. Unlike COX-1, mutating this residue to Ala, Phe, Pro, or Thr did not result in a significant loss of activity or substrate binding affinity. Determination of the L531F:AA crystal structure resulted in AA binding in the same global conformation in each monomer. We speculate that the mobility of the Leu-531 side chain increases the volume available at the opening of the cyclooxygenase channel and contributes to the observed ability of COX-2 to oxygenate a broad spectrum of fatty acid and fatty ester substrates.


  • Organizational Affiliation

    Hauptman-Woodward Medical Research Institute, Buffalo, New York 14203, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Prostaglandin G/H synthase 2
A, B
591Mus musculusMutation(s): 2 
Gene Names: Cox-2Cox2Pghs-bPtgs2Tis10
EC: 1.14.99.1
UniProt
Find proteins for Q05769 (Mus musculus)
Explore Q05769 
Go to UniProtKB:  Q05769
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ05769
Glycosylation
Glycosylation Sites: 3Go to GlyGen: Q05769-1
Sequence Annotations
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
C, D, E
2N-Glycosylation
Glycosylation Resources
GlyTouCan:  G42666HT
GlyCosmos:  G42666HT
GlyGen:  G42666HT
Entity ID: 3
MoleculeChains Length2D Diagram Glycosylation3D Interactions
alpha-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
F
3N-Glycosylation
Glycosylation Resources
GlyTouCan:  G62182OO
GlyCosmos:  G62182OO
GlyGen:  G62182OO
Small Molecules
Ligands 6 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
COH
Query on COH

Download Ideal Coordinates CCD File 
K [auth A],
S [auth B]
PROTOPORPHYRIN IX CONTAINING CO
C34 H32 Co N4 O4
AQTFKGDWFRRIHR-RGGAHWMASA-L
ACD
Query on ACD

Download Ideal Coordinates CCD File 
G [auth A],
O [auth B]
ARACHIDONIC ACID
C20 H32 O2
YZXBAPSDXZZRGB-DOFZRALJSA-N
BOG
Query on BOG

Download Ideal Coordinates CCD File 
M [auth A],
U [auth B]
octyl beta-D-glucopyranoside
C14 H28 O6
HEGSGKPQLMEBJL-RKQHYHRCSA-N
NAG
Query on NAG

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

Download Ideal Coordinates CCD File 
J [auth A],
N [auth A],
R [auth B]
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
AKR
Query on AKR

Download Ideal Coordinates CCD File 
H [auth A],
I [auth A],
P [auth B],
Q [auth B]
ACRYLIC ACID
C3 H4 O2
NIXOWILDQLNWCW-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.179 
  • R-Value Observed: 0.182 
  • Space Group: I 2 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 120.79α = 90
b = 133.04β = 90
c = 180.654γ = 90
Software Package:
Software NamePurpose
XDSdata scaling
PHASERphasing
REFMACrefinement
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-05-12
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Advisory, Atomic model, Data collection, Database references, Derived calculations, Structure summary
  • Version 2.1: 2021-10-13
    Changes: Database references, Structure summary
  • Version 2.2: 2023-09-06
    Changes: Data collection, Refinement description
  • Version 2.3: 2024-10-09
    Changes: Data collection, Structure summary