3M3N

Structure of a Longitudinal Actin Dimer Assembled by Tandem W Domains


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 7 Å

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structure of a longitudinal actin dimer assembled by tandem w domains: implications for actin filament nucleation.

Rebowski, G.Namgoong, S.Boczkowska, M.Leavis, P.C.Navaza, J.Dominguez, R.

(2010) J.Mol.Biol. 403: 11-23

  • DOI: 10.1016/j.jmb.2010.08.040
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Actin filament nucleators initiate polymerization in cells in a regulated manner. A common architecture among these molecules consists of tandem WASP homology 2 domains (W domains) that recruit three to four actin subunits to form a polymerization nu ...

    Actin filament nucleators initiate polymerization in cells in a regulated manner. A common architecture among these molecules consists of tandem WASP homology 2 domains (W domains) that recruit three to four actin subunits to form a polymerization nucleus. We describe a low-resolution crystal structure of an actin dimer assembled by tandem W domains, where the first W domain is cross-linked to Cys374 of the actin subunit bound to it, whereas the last W domain is followed by the C-terminal pointed end-capping helix of thymosin β4. While the arrangement of actin subunits in the dimer resembles that of a long-pitch helix of the actin filament, important differences are observed. These differences result from steric hindrance of the W domain with intersubunit contacts in the actin filament. We also determined the structure of the first W domain of Vibrio parahaemolyticus VopL cross-linked to actin Cys374 and show it to be nearly identical with non-cross-linked W-Actin structures. This result validates the use of cross-linking as a tool for the study of actin nucleation complexes, whose natural tendency to polymerize interferes with most structural methods. Combined with a biochemical analysis of nucleation, the structures may explain why nucleators based on tandem W domains with short inter-W linkers have relatively weak activity, cannot stay bound to filaments after nucleation, and are unlikely to influence filament elongation. The findings may also explain why nucleation-promoting factors of the Arp2/3 complex, which are related to tandem-W-domain nucleators, are ejected from branch junctions after nucleation. We finally show that the simple addition of the C-terminal pointed end-capping helix of thymosin β4 to tandem W domains can change their activity from actin filament nucleation to monomer sequestration.


    Organizational Affiliation

    Department of Physiology, University of Pennsylvania School of Medicine, 3700 Hamilton Walk, Philadelphia, PA 19104-6085, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Actin, alpha skeletal muscle
A, B
375Oryctolagus cuniculusMutation(s): 0 
Gene Names: ACTA1 (ACTA)
Find proteins for P68135 (Oryctolagus cuniculus)
Go to Gene View: ACTA1
Go to UniProtKB:  P68135
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Neural Wiskott-Aldrich syndrome protein
W
101Mus musculusMutation(s): 3 
Gene Names: Wasl, Tmsb4x (Ptmb4, Tmsb4)
Find proteins for Q91YD9 (Mus musculus)
Go to UniProtKB:  Q91YD9
Find proteins for P20065 (Mus musculus)
Go to UniProtKB:  P20065
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ATP
Query on ATP

Download SDF File 
Download CCD File 
A, B
ADENOSINE-5'-TRIPHOSPHATE
C10 H16 N5 O13 P3
ZKHQWZAMYRWXGA-KQYNXXCUSA-N
 Ligand Interaction
CA
Query on CA

Download SDF File 
Download CCD File 
A, B
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
HIC
Query on HIC
A, B
L-PEPTIDE LINKINGC7 H11 N3 O2HIS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 7 Å
  • Space Group: P 65 2 2
Unit Cell:
Length (Å)Angle (°)
a = 100.743α = 90.00
b = 100.743β = 90.00
c = 458.839γ = 120.00
Software Package:
Software NamePurpose
PHENIXmodel building
HKL-2000data scaling
HKL-2000data collection
AMoREphasing
HKL-2000data reduction
PHENIXphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-07-28
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2017-07-26
    Type: Refinement description, Source and taxonomy