1SQM

STRUCTURE OF [R563A] LEUKOTRIENE A4 HYDROLASE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.190 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Leukotriene A4 hydrolase: identification of a common carboxylate recognition site for the epoxide hydrolase and aminopeptidase substrates

Rudberg, P.C.Tholander, F.O.T.Andberg, M.Thunnissen, M.M.G.M.

(2004) J.Biol.Chem. 279: 27376-27382

  • DOI: 10.1074/jbc.M401031200
  • Also Cited By: 2R59, 3B7R, 3B7S, 3B7T, 3B7U

  • PubMed Abstract: 
  • Leukotriene (LT) A(4) hydrolase is a bifunctional zinc metalloenzyme, which converts LTA(4) into the neutrophil chemoattractant LTB(4) and also exhibits an anion-dependent aminopeptidase activity. In the x-ray crystal structure of LTA(4) hydrolase, A ...

    Leukotriene (LT) A(4) hydrolase is a bifunctional zinc metalloenzyme, which converts LTA(4) into the neutrophil chemoattractant LTB(4) and also exhibits an anion-dependent aminopeptidase activity. In the x-ray crystal structure of LTA(4) hydrolase, Arg(563) and Lys(565) are found at the entrance of the active center. Here we report that replacement of Arg(563), but not Lys(565), leads to complete abrogation of the epoxide hydrolase activity. However, mutations of Arg(563) do not seem to affect substrate binding strength, because values of K(i) for LTA(4) are almost identical for wild type and (R563K)LTA(4) hydrolase. These results are supported by the 2.3-A crystal structure of (R563A)LTA(4) hydrolase, which does not reveal structural changes that can explain the complete loss of enzyme function. For the aminopeptidase reaction, mutations of Arg(563) reduce the catalytic activity (V(max) = 0.3-20%), whereas mutations of Lys(565) have limited effect on catalysis (V(max) = 58-108%). However, in (K565A)- and (K565M)LTA(4) hydrolase, i.e. mutants lacking a positive charge, values of the Michaelis constant for alanine-p-nitroanilide increase significantly (K(m) = 480-640%). Together, our data indicate that Arg(563) plays an unexpected, critical role in the epoxide hydrolase reaction, presumably in the positioning of the carboxylate tail to ensure perfect substrate alignment along the catalytic elements of the active site. In the aminopeptidase reaction, Arg(563) and Lys(565) seem to cooperate to provide sufficient binding strength and productive alignment of the substrate. In conclusion, Arg(563) and Lys(565) possess distinct roles as carboxylate recognition sites for two chemically different substrates, each of which is turned over in separate enzymatic reactions catalyzed by LTA(4) hydrolase.


    Organizational Affiliation

    Department of Medical Biochemistry and Biophysics, Division of Chemistry II, Karolinska Institutet, S-171 77 Stockholm, Sweden.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
LEUKOTRIENE A-4 HYDROLASE
A
610Homo sapiensGene Names: LTA4H (LTA4)
EC: 3.3.2.6
Find proteins for P09960 (Homo sapiens)
Go to Gene View: LTA4H
Go to UniProtKB:  P09960
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

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A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
YB
Query on YB

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Download CCD File 
A
YTTERBIUM (III) ION
Yb
AWSFICBXMUKWSK-UHFFFAOYSA-N
 Ligand Interaction
IMD
Query on IMD

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Download CCD File 
A
IMIDAZOLE
C3 H5 N2
RAXXELZNTBOGNW-UHFFFAOYSA-O
 Ligand Interaction
ACY
Query on ACY

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A
ACETIC ACID
C2 H4 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.190 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 78.000α = 90.00
b = 86.850β = 90.00
c = 98.950γ = 90.00
Software Package:
Software NamePurpose
CCP4data scaling
CNSrefinement
CNSphasing
MAR345data collection
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-08-03
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-11
    Type: Data collection, Refinement description