1S8I

Crystal structure of Lys49-Phospholipase A2 from Agkistrodon contortrix laticinctus, second fatty acid free form


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.61 Å
  • R-Value Free: 0.205 
  • R-Value Work: 0.186 
  • R-Value Observed: 0.187 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

A Molecular Mechanism for Lys49-Phospholipase A2 Activity Based on Ligand-induced Conformational Change.

Ambrosio, A.L.B.Nonato, M.C.Selistre de Araujo, H.S.Arni, R.Ward, R.J.Ownby, C.L.de Souza, D.H.F.Garratt, R.C.

(2005) J Biol Chem 280: 7326-7335

  • DOI: 10.1074/jbc.M410588200
  • Primary Citation of Related Structures:  
    1S8I, 1S8H, 1S8G

  • PubMed Abstract: 
  • Agkistrodon contortrix laticinctus myotoxin is a Lys(49)-phospholipase A(2) (EC 3.1.1.4) isolated from the venom of the serpent A. contortrix laticinctus (broad-banded copperhead). We present here three monomeric crystal structures of the myotoxin, o ...

    Agkistrodon contortrix laticinctus myotoxin is a Lys(49)-phospholipase A(2) (EC 3.1.1.4) isolated from the venom of the serpent A. contortrix laticinctus (broad-banded copperhead). We present here three monomeric crystal structures of the myotoxin, obtained under different crystallization conditions. The three forms present notable structural differences and reveal that the presence of a ligand in the active site (naturally presumed to be a fatty acid) induces the exposure of a hydrophobic surface (the hydrophobic knuckle) toward the C terminus. The knuckle in A. contortrix laticinctus myotoxin involves the side chains of Phe(121) and Phe(124) and is a consequence of the formation of a canonical structure for the main chain within the region of residues 118-125. Comparison with other Lys(49)-phospholipase A(2) myotoxins shows that although the knuckle is a generic structural motif common to all members of the family, it is not readily recognizable by simple sequence analyses. An activation mechanism is proposed that relates fatty acid retention at the active site to conformational changes within the C-terminal region, a part of the molecule that has long been associated with Ca(2+)-independent membrane damaging activity and myotoxicity. This provides, for the first time, a direct structural connection between the phospholipase "active site" and the C-terminal "myotoxic site," justifying the otherwise enigmatic conservation of the residues of the former in supposedly catalytically inactive molecules.


    Organizational Affiliation

    Centro de Biotecnologia Molecular Estrutural, Instituto de Física de São Carlos, USP, São Carlos-SP CEP 13560-970, Brazil.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Phospholipase A2 homologA121Agkistrodon contortrix laticinctusMutation(s): 0 
EC: 3.1.1.4
Find proteins for P49121 (Agkistrodon contortrix laticinctus)
Explore P49121 
Go to UniProtKB:  P49121
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.61 Å
  • R-Value Free: 0.205 
  • R-Value Work: 0.186 
  • R-Value Observed: 0.187 
  • Space Group: P 41 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 70.57α = 90
b = 70.57β = 90
c = 57.45γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
DENZOdata reduction
SCALEPACKdata scaling
SHELXDphasing
SHARPphasing
ARP/wARPmodel building

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-02-10
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Advisory, Version format compliance