2UUH

Crystal structure of Human Leukotriene C4 Synthase in complex with substrate glutathione


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.183 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural Basis for Synthesis of Inflammatory Mediators by Human Leukotriene C4 Synthase.

Martinez Molina, D.Wetterholm, A.Kohl, A.Mccarthy, A.A.Niegowski, D.Ohlson, E.Hammarberg, T.Eshaghi, S.Haeggstrom, J.Z.Nordlund, P.

(2007) Nature 448: 613

  • DOI: 10.1038/nature06009
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Cysteinyl leukotrienes are key mediators in inflammation and have an important role in acute and chronic inflammatory diseases of the cardiovascular and respiratory systems, in particular bronchial asthma. In the biosynthesis of cysteinyl leukotriene ...

    Cysteinyl leukotrienes are key mediators in inflammation and have an important role in acute and chronic inflammatory diseases of the cardiovascular and respiratory systems, in particular bronchial asthma. In the biosynthesis of cysteinyl leukotrienes, conversion of arachidonic acid forms the unstable epoxide leukotriene A4 (LTA4). This intermediate is conjugated with glutathione (GSH) to produce leukotriene C4 (LTC4) in a reaction catalysed by LTC4 synthase: this reaction is the key step in cysteinyl leukotriene formation. Here we present the crystal structure of the human LTC4 synthase in its apo and GSH-complexed forms to 2.00 and 2.15 A resolution, respectively. The structure reveals a homotrimer, where each monomer is composed of four transmembrane segments. The structure of the enzyme in complex with substrate reveals that the active site enforces a horseshoe-shaped conformation on GSH, and effectively positions the thiol group for activation by a nearby arginine at the membrane-enzyme interface. In addition, the structure provides a model for how the omega-end of the lipophilic co-substrate is pinned at one end of a hydrophobic cleft, providing a molecular 'ruler' to align the reactive epoxide at the thiol of glutathione. This provides new structural insights into the mechanism of LTC4 formation, and also suggests that the observed binding and activation of GSH might be common for a family of homologous proteins important for inflammatory and detoxification responses.


    Organizational Affiliation

    Division of Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
LEUKOTRIENE C4 SYNTHASE
A
156Homo sapiensMutation(s): 0 
Gene Names: LTC4S
EC: 4.4.1.20
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Membrane-Associated Proteins in Eicosanoid and Glutathione Metabolism (MAPEG)
Protein: 
Leukotriene LTC4 Synthase in complex with glutathione
Find proteins for Q16873 (Homo sapiens)
Go to Gene View: LTC4S
Go to UniProtKB:  Q16873
Small Molecules
Ligands 6 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

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A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
GSH
Query on GSH

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Download CCD File 
A
GLUTATHIONE
C10 H17 N3 O6 S
RWSXRVCMGQZWBV-WDSKDSINSA-N
 Ligand Interaction
PAM
Query on PAM

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A
PALMITOLEIC ACID
C16 H30 O2
SECPZKHBENQXJG-FPLPWBNLSA-N
 Ligand Interaction
NI
Query on NI

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A
NICKEL (II) ION
Ni
VEQPNABPJHWNSG-UHFFFAOYSA-N
 Ligand Interaction
PLM
Query on PLM

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

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Download CCD File 
A
DODECYL-ALPHA-D-MALTOSIDE
C24 H46 O11
NLEBIOOXCVAHBD-YHBSTRCHSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.183 
  • Space Group: F 2 3
Unit Cell:
Length (Å)Angle (°)
a = 169.940α = 90.00
b = 169.940β = 90.00
c = 169.940γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-07-17
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Advisory, Version format compliance
  • Version 1.2: 2011-12-07
    Type: Advisory, Atomic model, Derived calculations, Non-polymer description, Other