3QH0

X-ray crystal structure of palmitic acid bound to the cyclooxygenase channel of cyclooxygenase-2


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.199 
  • R-Value Work: 0.159 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Human cyclooxygenase-2 is a sequence homodimer that functions as a conformational heterodimer.

Dong, L.Vecchio, A.J.Sharma, N.P.Jurban, B.J.Malkowski, M.G.Smith, W.L.

(2011) J.Biol.Chem. 286: 19035-19046

  • DOI: 10.1074/jbc.M111.231969

  • PubMed Abstract: 
  • Prostaglandin endoperoxide H synthases 1 and 2, also known as cyclooxygenases (COXs) 1 and 2, convert arachidonic acid (AA) to prostaglandin endoperoxide H(2). Prostaglandin endoperoxide H synthases are targets of nonspecific nonsteroidal anti-inflam ...

    Prostaglandin endoperoxide H synthases 1 and 2, also known as cyclooxygenases (COXs) 1 and 2, convert arachidonic acid (AA) to prostaglandin endoperoxide H(2). Prostaglandin endoperoxide H synthases are targets of nonspecific nonsteroidal anti-inflammatory drugs and COX-2-specific inhibitors called coxibs. PGHS-2 is a sequence homodimer. Each monomer has a peroxidase and a COX active site. We find that human PGHS-2 functions as a conformational heterodimer having a catalytic monomer (E(cat)) and an allosteric monomer (E(allo)). Heme binds tightly only to the peroxidase site of E(cat), whereas substrates, as well as certain inhibitors (e.g. celecoxib), bind the COX site of E(cat). E(cat) is regulated by E(allo) in a manner dependent on what ligand is bound to E(allo). Substrate and nonsubstrate fatty acids (FAs) and some COX inhibitors (e.g. naproxen) preferentially bind to the COX site of E(allo). AA can bind to E(cat) and E(allo), but the affinity of AA for E(allo) is 25 times that for E(cat). Palmitic acid, an efficacious stimulator of human PGHS-2, binds only E(allo) in palmitic acid/murine PGHS-2 co-crystals. Nonsubstrate FAs can potentiate or attenuate actions of COX inhibitors depending on the FA and whether the inhibitor binds E(cat) or E(allo). Our studies suggest that the concentration and composition of the free FA pool in the environment in which PGHS-2 functions in cells, the FA tone, is a key factor regulating PGHS-2 activity and its responses to COX inhibitors. We suggest that differences in FA tone occurring with different diets will likely affect both base-line prostanoid synthesis and responses to COX inhibitors.


    Organizational Affiliation

    Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Prostaglandin G/H synthase 2
A, B
610Mus musculusGene Names: Ptgs2 (Cox-2, Cox2, Pghs-b, Tis10)
EC: 1.14.99.1
Find proteins for Q05769 (Mus musculus)
Go to UniProtKB:  Q05769
Small Molecules
Ligands 9 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MAN
Query on MAN

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A
ALPHA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-PQMKYFCFSA-N
 Ligand Interaction
COH
Query on COH

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A, B
PROTOPORPHYRIN IX CONTAINING CO
C34 H32 Co N4 O4
AQTFKGDWFRRIHR-CTESUSPADG
 Ligand Interaction
AKR
Query on AKR

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A
ACRYLIC ACID
C3 H4 O2
NIXOWILDQLNWCW-UHFFFAOYSA-N
 Ligand Interaction
EDO
Query on EDO

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A, B
1,2-ETHANEDIOL
ETHYLENE GLYCOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
HSQ
Query on HSQ

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A
2-(acetylamino)-2-deoxy-alpha-L-idopyranose
C8 H15 N O6
OVRNDRQMDRJTHS-SLBCVNJHSA-N
 Ligand Interaction
NDG
Query on NDG

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B
2-(ACETYLAMINO)-2-DEOXY-A-D-GLUCOPYRANOSE
C8 H15 N O6
OVRNDRQMDRJTHS-PVFLNQBWSA-N
 Ligand Interaction
NAG
Query on NAG

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A, B
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
PLM
Query on PLM

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A
PALMITIC ACID
C16 H32 O2
IPCSVZSSVZVIGE-UHFFFAOYSA-N
 Ligand Interaction
BOG
Query on BOG

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A
B-OCTYLGLUCOSIDE
C14 H28 O6
HEGSGKPQLMEBJL-RKQHYHRCSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
FATIC50: >500000 nM (86) BINDINGDB
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.199 
  • R-Value Work: 0.159 
  • Space Group: I 2 2 2
Unit Cell:
Length (Å)Angle (°)
a = 121.906α = 90.00
b = 130.888β = 90.00
c = 179.968γ = 90.00
Software Package:
Software NamePurpose
Adxvdata processing
REFMACrefinement
PHASERphasing
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-04-13
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2017-11-08
    Type: Refinement description