4KF3

Crystal Structure of Myotoxin II (MjTX-II), a myotoxic Lys49-phospholipase A2 from Bothrops moojeni.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.92 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.227 
  • R-Value Observed: 0.227 

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This is version 1.1 of the entry. See complete history


Literature

Structural and functional studies with mytoxin II from Bothrops moojeni reveal remarkable similarities and differences compared to other catalytically inactive phospholipases A2-like.

Salvador, G.H.Cavalcante, W.L.Dos Santos, J.I.Gallacci, M.Soares, A.M.Fontes, M.R.

(2013) Toxicon 72C: 52-63

  • DOI: 10.1016/j.toxicon.2013.06.013
  • Primary Citation of Related Structures:  
    4KF3

  • PubMed Abstract: 
  • Lys49-phospholipases A₂ (Lys49-PLA₂s) are proteins found in bothropic snake venoms (Viperidae family) and belong to a class of proteins which presents a phospholipase A2 scaffold but are catalytically inactive. These proteins (also known as PLA₂s-like toxins) exert a pronounced local myotoxic effect and are not neutralized by antivenom, being their study relevant in terms of medical and scientific interest ...

    Lys49-phospholipases A₂ (Lys49-PLA₂s) are proteins found in bothropic snake venoms (Viperidae family) and belong to a class of proteins which presents a phospholipase A2 scaffold but are catalytically inactive. These proteins (also known as PLA₂s-like toxins) exert a pronounced local myotoxic effect and are not neutralized by antivenom, being their study relevant in terms of medical and scientific interest. Despite of the several studies reported in the literature for this class of proteins only a partial consensus has been achieved concerning their functional-structural relationships. In this work, we present a comprehensive structural and functional study with the MjTX-II, a dimeric Lys49-PLA₂ from Bothrops moojeni venom which includes: (i) high-resolution crystal structure; (ii) dynamic light scattering and bioinformatics studies in order to confirm its biological assembly; (iii) myographic and electrophysiological studies and, (iv) comparative studies with other Lys49-PLA₂s. These comparative analyses let us to get important insights into the role of Lys122 amino acid, previously indicated as responsible for Lys49-PLA₂s catalytic inactivity and added important elements to establish the correct biological assembly for this class of proteins. Furthermore, we show two unique sequential features of MjTX-II (an amino acid insertion and a mutation) in comparison to all bothropic Lys49-PLA₂s that lead to a distinct way of ligand binding at the toxin's hydrophobic channel and also, allowed the presence of an additional ligand molecule in this region. These facts suggest a possible particular mode of binding for long-chain ligands that interacts with MjTX-II hydrophobic channel, a feature that may directly affect the design of structure-based ligands for Lys49-PLA₂s.


    Organizational Affiliation

    Depto. de Física e Biofísica, Instituto de Biociências, UNESP-Univ Estadual Paulista, Botucatu, SP, Brazil.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Basic phospholipase A2 homolog 2B [auth A], A [auth B]122Bothrops moojeniMutation(s): 0 
UniProt
Find proteins for Q9I834 (Bothrops moojeni)
Explore Q9I834 
Go to UniProtKB:  Q9I834
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.92 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.227 
  • R-Value Observed: 0.227 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 49.999α = 90
b = 62.169β = 90
c = 86.007γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
MOLREPphasing
CNSrefinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-07-17
    Type: Initial release
  • Version 1.1: 2013-07-24
    Changes: Database references