1BWR

PROBING THE SUBSTRATE SPECIFICITY OF THE INTRACELLULAR BRAIN PLATELET-ACTIVATING FACTOR ACETYLHYDROLASE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.205 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Probing the Substrate Specificity of the Intracellular Brain Platelet-Activating Factor Acetylhydrolase

Ho, Y.S.Sheffield, P.J.Masuyama, J.Arai, H.Li, J.Aoki, J.Inoue, K.Derewenda, U.Derewenda, Z.S.

(1999) Protein Eng. 12: 693-700

  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Platelet-activating factor acetylhydrolases (PAF-AHs) are unique PLA2s which hydrolyze the sn-2 ester linkage in PAF-like phospholipids with a marked preference for very short acyl chains, typically acetyl. The recent solution of the crystal structur ...

    Platelet-activating factor acetylhydrolases (PAF-AHs) are unique PLA2s which hydrolyze the sn-2 ester linkage in PAF-like phospholipids with a marked preference for very short acyl chains, typically acetyl. The recent solution of the crystal structure of the alpha(1) catalytic subunit of isoform Ib of bovine brain intracellular PAF-AH at 1.7 A resolution paved the way for a detailed examination of the molecular basis of substrate specificity in this enzyme. The crystal structure suggests that the side chains of Thr103, Leu48 and Leu194 are involved in substrate recognition. Three single site mutants (L48A, T103S and L194A) were overexpressed and their structures were solved to 2.3 A resolution or better by X-ray diffraction methods. Enzyme kinetics showed that, compared with wild-type protein, all three mutants have higher relative activity against phospholipids with sn-2 acyl chains longer than an acetyl. However, for each of the mutants we observed an unexpected and substantial reduction in the V(max) of the reaction. These results are consistent with the model in which residues Leu48, Thr103 and Leu194 indeed contribute to substrate specificity and in addition suggest that the integrity of the specificity pocket is critical for the expression of full catalytic function, thus conferring very high substrate selectivity on the enzyme.


    Related Citations: 
    • Brain Acetylhydrolase that Inactivates Platelet-Activating Factor is a G-Protein-Like Trimer
      Ho, Y.S.,Swenson, L.,Derewenda, U.,Serre, L.,Wei, Y.,Dauter, Z.,Hattori, M.,Adachi, T.,Aoki, J.,Arai, H.,Inoue, K.,Derewenda, Z.S.
      (1997) Nature 385: 89


    Organizational Affiliation

    Department of Molecular Physiology and Biological Physics, University of Virginia, Health Sciences Center, P.O. Box 10011, Charlottesville, VA 22906-0011, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PLATELET-ACTIVATING FACTOR ACETYLHYDROLASE
A
233Bos taurusMutation(s): 1 
Gene Names: PAFAH1B3 (PAFAHG)
EC: 3.1.1.47
Find proteins for Q29460 (Bos taurus)
Go to Gene View: PAFAH1B3
Go to UniProtKB:  Q29460
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.205 
  • Space Group: P 31 2 1
Unit Cell:
Length (Å)Angle (°)
a = 81.056α = 90.00
b = 81.056β = 90.00
c = 72.622γ = 120.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
AMoREphasing
REFMACrefinement
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-05-18
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance