4CBU

Crystal structure of Plasmodium falciparum actin I


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.30 Å
  • R-Value Free: 0.153 
  • R-Value Work: 0.120 
  • R-Value Observed: 0.121 

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This is version 2.0 of the entry. See complete history


Literature

Structural Differences Explain Diverse Functions of Plasmodium Actins.

Vahokoski, J.Bhargav, S.P.Desfosses, A.Andreadaki, M.Kumpula, E.Martinez, S.M.Ignatev, A.Lepper, S.Frischknecht, F.Siden-Kiamos, I.Sachse, C.Kursula, I.

(2014) PLoS Pathog 10: 4091

  • DOI: https://doi.org/10.1371/journal.ppat.1004091
  • Primary Citation of Related Structures:  
    4CBU, 4CBW, 4CBX

  • PubMed Abstract: 

    Actins are highly conserved proteins and key players in central processes in all eukaryotic cells. The two actins of the malaria parasite are among the most divergent eukaryotic actins and also differ from each other more than isoforms in any other species. Microfilaments have not been directly observed in Plasmodium and are presumed to be short and highly dynamic. We show that actin I cannot complement actin II in male gametogenesis, suggesting critical structural differences. Cryo-EM reveals that Plasmodium actin I has a unique filament structure, whereas actin II filaments resemble canonical F-actin. Both Plasmodium actins hydrolyze ATP more efficiently than α-actin, and unlike any other actin, both parasite actins rapidly form short oligomers induced by ADP. Crystal structures of both isoforms pinpoint several structural changes in the monomers causing the unique polymerization properties. Inserting the canonical D-loop to Plasmodium actin I leads to the formation of long filaments in vitro. In vivo, this chimera restores gametogenesis in parasites lacking actin II, suggesting that stable filaments are required for exflagellation. Together, these data underline the divergence of eukaryotic actins and demonstrate how structural differences in the monomers translate into filaments with different properties, implying that even eukaryotic actins have faced different evolutionary pressures and followed different paths for developing their polymerization properties.


  • Organizational Affiliation

    Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Actin-1378Plasmodium falciparumMutation(s): 0 
Gene Names: ACT1ACTIPF3D7_1246200PFL2215w
EC: 3.6.4
UniProt
Find proteins for Q8I4X0 (Plasmodium falciparum (isolate 3D7))
Explore Q8I4X0 
Go to UniProtKB:  Q8I4X0
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ8I4X0
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
GelsolinB [auth G]127Mus musculusMutation(s): 0 
Gene Names: GsnGsb
UniProt
Find proteins for P13020 (Mus musculus)
Explore P13020 
Go to UniProtKB:  P13020
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP13020
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.30 Å
  • R-Value Free: 0.153 
  • R-Value Work: 0.120 
  • R-Value Observed: 0.121 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 68.98α = 90
b = 110.3β = 90
c = 71.48γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
XSCALEdata scaling
PHASERphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Revision History  (Full details and data files)

  • Version 1.0: 2014-04-30
    Type: Initial release
  • Version 2.0: 2024-05-08
    Changes: Atomic model, Data collection, Database references, Derived calculations, Other, Source and taxonomy, Structure summary