4UV6

Crystal structure of apical membrane antigen 1 from Plasmodium knowlesi


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.45 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.171 
  • R-Value Observed: 0.172 

wwPDB Validation 3D Report Full Report



Literature

Crystal Structure of Plasmodium Knowlesi Apical Membrane Antigen 1 and its Complex with an Invasion-Inhibitory Monoclonal Antibody.

Vulliez-Le Normand, B.Faber, B.W.Saul, F.A.Van Der Eijk, M.Thomas, A.W.Singh, B.Kocken, C.H.M.Bentley, G.A.

(2015) PLoS One 10: 23567

  • DOI: 10.1371/journal.pone.0123567
  • Primary Citation of Related Structures:  
    4UV6, 4UAO

  • PubMed Abstract: 
  • The malaria parasite Plasmodium knowlesi, previously associated only with infection of macaques, is now known to infect humans as well and has become a significant public health problem in Southeast Asia. This species should therefore be targeted in ...

    The malaria parasite Plasmodium knowlesi, previously associated only with infection of macaques, is now known to infect humans as well and has become a significant public health problem in Southeast Asia. This species should therefore be targeted in vaccine and therapeutic strategies against human malaria. Apical Membrane Antigen 1 (AMA1), which plays a role in Plasmodium merozoite invasion of the erythrocyte, is currently being pursued in human vaccine trials against P. falciparum. Recent vaccine trials in macaques using the P. knowlesi orthologue PkAMA1 have shown that it protects against infection by this parasite species and thus should be developed for human vaccination as well. Here, we present the crystal structure of Domains 1 and 2 of the PkAMA1 ectodomain, and of its complex with the invasion-inhibitory monoclonal antibody R31C2. The Domain 2 (D2) loop, which is displaced upon binding the Rhoptry Neck Protein 2 (RON2) receptor, makes significant contacts with the antibody. R31C2 inhibits binding of the Rhoptry Neck Protein 2 (RON2) receptor by steric blocking of the hydrophobic groove and by preventing the displacement of the D2 loop which is essential for exposing the complete binding site on AMA1. R31C2 recognizes a non-polymorphic epitope and should thus be cross-strain reactive. PkAMA1 is much less polymorphic than the P. falciparum and P. vivax orthologues. Unlike these two latter species, there are no polymorphic sites close to the RON2-binding site of PkAMA1, suggesting that P. knowlesi has not developed a mechanism of immune escape from the host's humoral response to AMA1.


    Organizational Affiliation

    Institut Pasteur, Unité d'Immunologie Structurale, Département de Biologie Structurale et Chimie, Paris, France; CNRS URA 2185, Paris, France.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
APICAL MEROZOITE ANTIGEN 1AB370Plasmodium knowlesi strain HMutation(s): 4 
Gene Names: PKNH_0931500
Find proteins for A0A384KGX8 (Plasmodium knowlesi (strain H))
Explore A0A384KGX8 
Go to UniProtKB:  A0A384KGX8
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.45 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.171 
  • R-Value Observed: 0.172 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 90.32α = 90
b = 105.7β = 98.04
c = 104.75γ = 90
Software Package:
Software NamePurpose
BUSTERrefinement
XDSdata reduction
SCALAdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-04-29
    Type: Initial release