2UUI

Crystal structure of Human Leukotriene C4 Synthase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.198 

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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: https://doi.org/10.1038/nature06009
  • Primary Citation of Related Structures:  
    2UUH, 2UUI

  • 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 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:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
LEUKOTRIENE C4 SYNTHASE156Homo sapiensMutation(s): 0 
EC: 4.4.1.20
Membrane Entity: Yes 
UniProt & NIH Common Fund Data Resources
Find proteins for Q16873 (Homo sapiens)
Explore Q16873 
Go to UniProtKB:  Q16873
PHAROS:  Q16873
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ16873
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
LMT
Query on LMT

Download Ideal Coordinates CCD File 
E [auth A],
F [auth A]
DODECYL-BETA-D-MALTOSIDE
C24 H46 O11
NLEBIOOXCVAHBD-QKMCSOCLSA-N
PLM
Query on PLM

Download Ideal Coordinates CCD File 
G [auth A]
H [auth A]
I [auth A]
J [auth A]
K [auth A]
G [auth A],
H [auth A],
I [auth A],
J [auth A],
K [auth A],
L [auth A],
M [auth A],
N [auth A],
Q [auth A],
R [auth A],
S [auth A],
T [auth A],
U [auth A],
V [auth A]
PALMITIC ACID
C16 H32 O2
IPCSVZSSVZVIGE-UHFFFAOYSA-N
SO4
Query on SO4

Download Ideal Coordinates CCD File 
O [auth A],
P [auth A]
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
NI
Query on NI

Download Ideal Coordinates CCD File 
B [auth A],
C [auth A],
D [auth A]
NICKEL (II) ION
Ni
VEQPNABPJHWNSG-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.198 
  • Space Group: F 2 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 169.67α = 90
b = 169.67β = 90
c = 169.67γ = 90
Software Package:
Software NamePurpose
REFMACrefinement

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Revision History  (Full details and data files)

  • Version 1.0: 2007-07-17
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance