3Q2B

Crystal Structure of an Actin Depolymerizing Factor


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.218 
  • R-Value Work: 0.193 
  • R-Value Observed: 0.194 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Minimal requirements for actin filament disassembly revealed by structural analysis of malaria parasite actin-depolymerizing factor 1

Wong, W.Skau, C.T.Marapana, D.S.Hanssen, E.Taylor, N.L.Riglar, D.T.Zuccala, E.S.Angrisano, F.Lewis, H.Catimel, B.Clarke, O.B.Kershaw, N.J.Perugini, M.A.Kovar, D.R.Gulbis, J.M.Baum, J.

(2011) Proc Natl Acad Sci U S A 108: 9869-9874

  • DOI: 10.1073/pnas.1018927108
  • Primary Citation of Related Structures:  
    3Q2B

  • PubMed Abstract: 
  • Malaria parasite cell motility is a process that is dependent on the dynamic turnover of parasite-derived actin filaments. Despite its central role, actin's polymerization state is controlled by a set of identifiable regulators that is markedly reduced compared with those of other eukaryotic cells ...

    Malaria parasite cell motility is a process that is dependent on the dynamic turnover of parasite-derived actin filaments. Despite its central role, actin's polymerization state is controlled by a set of identifiable regulators that is markedly reduced compared with those of other eukaryotic cells. In Plasmodium falciparum, the most virulent species that affects humans, this minimal repertoire includes two members of the actin-depolymerizing factor/cofilin (AC) family of proteins, P. falciparum actin-depolymerizing factor 1 (PfADF1) and P. falciparum actin-depolymerizing factor 2. This essential class of actin regulator is involved in the control of filament dynamics at multiple levels, from monomer binding through to filament depolymerization and severing. Previous biochemical analyses have suggested that PfADF1 sequesters monomeric actin but, unlike most eukaryotic counterparts, has limited potential to bind or depolymerize filaments. The molecular basis for these unusual properties and implications for parasite cell motility have not been established. Here we present the crystal structure of an apicomplexan AC protein, PfADF1. We show that PfADF1 lacks critical residues previously implicated as essential for AC-mediated actin filament binding and disassembly, having a substantially reduced filament-binding loop and C-terminal α4 helix. Despite this divergence in structure, we demonstrate that PfADF1 is capable of efficient actin filament severing. Furthermore, this severing occurs despite PfADF1's low binding affinity for filaments. Comparative structural analysis along with biochemical and microscopy evidence establishes that severing is reliant on the availability of an exposed basic residue in the filament-binding loop, a conserved minimal requirement that defines AC-mediated filament disassembly across eukaryotic cells.


    Organizational Affiliation

    Infection and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Cofilin/actin-depolymerizing factor homolog 1A124Plasmodium falciparum HB3Mutation(s): 0 
UniProt
Find proteins for P86292 (Plasmodium falciparum (isolate HB3))
Explore P86292 
Go to UniProtKB:  P86292
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
TAR
Query on TAR

Download Ideal Coordinates CCD File 
C [auth A], D [auth A]D(-)-TARTARIC ACID
C4 H6 O6
FEWJPZIEWOKRBE-LWMBPPNESA-N
 Ligand Interaction
BME
Query on BME

Download Ideal Coordinates CCD File 
B [auth A], E [auth A]BETA-MERCAPTOETHANOL
C2 H6 O S
DGVVWUTYPXICAM-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.218 
  • R-Value Work: 0.193 
  • R-Value Observed: 0.194 
  • Space Group: P 43 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 38.97α = 90
b = 38.97β = 90
c = 142.4γ = 90
Software Package:
Software NamePurpose
ADSCdata collection
MOLREPphasing
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-06-01
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance