1QLL

Piratoxin-II (Prtx-II) - a K49 PLA2 from Bothrops pirajai


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.04 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.176 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural Basis for Low Catalytic Activity in Lys49 Phospholipases A2-A Hypothesis: The Crystal Structure of Piratoxin II Complexed to Fatty Acid

Lee, W.H.Da Silva Giotto, M.T.Marangoni, S.Toyama, M.H.Polikarpov, I.Garratt, R.C.

(2001) Biochemistry 40: 28


  • PubMed Abstract: 
  • Asp49 plays a fundamental role in supporting catalysis by phospholipases A2 by coordinating the calcium ion which aids in the stabilization of the tetrahedral intermediate. In several myotoxins from the venoms of Viperidae snakes, this aspartic acid ...

    Asp49 plays a fundamental role in supporting catalysis by phospholipases A2 by coordinating the calcium ion which aids in the stabilization of the tetrahedral intermediate. In several myotoxins from the venoms of Viperidae snakes, this aspartic acid is substituted by lysine. The loss of calcium binding capacity by these mutants has become regarded as the standard explanation for their greatly reduced or nonexistent phospholipolytic activity. Here we describe the crystal structure of one such Lys49 PLA2, piratoxin-II, in which a fatty acid molecule is observed within the substrate channel. This suggests that such toxins may be active enzymes in which catalysis is interrupted at the stage of substrate release. Comparison of the present structure with other PLA2s, both active and inactive, identifies Lys122 as one of the likely causes of the increased affinity for fatty acid in Lys49 enzymes. Its interaction with the mainchain carbonyl of Cys29 is expected to lead to hyperpolarization of the peptide bond between residues 29 and 30 leading to an increased affinity for the fatty acid headgroup. This strongly bound fatty acid may serve as an anchor to secure the toxin within the membrane thus facilitating its pathological effects.


    Organizational Affiliation

    Laboratório Nacional de Luz Síncrotron, Caixa Postal 6192, 13083-970 Campinas, São Paulo, Brazil.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PHOSPHOLIPASE A2
A, B
121Bothrops pirajaiMutation(s): 0 
Find proteins for P82287 (Bothrops pirajai)
Go to UniProtKB:  P82287
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
TDA
Query on TDA

Download SDF File 
Download CCD File 
A, B
N-TRIDECANOIC ACID
C13 H26 O2
SZHOJFHSIKHZHA-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.04 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.176 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 46.190α = 90.00
b = 60.360β = 96.05
c = 58.740γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
AMoREphasing
REFMACrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-09-07
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance