1M4J

CRYSTAL STRUCTURE OF THE N-TERMINAL ADF-H DOMAIN OF MOUSE TWINFILIN ISOFORM-1


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.232 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural Conservation Between the Actin Monomer-binding Sites of Twinfilin and Actin-depolymerizing Factor (ADF)/Cofilin

Paavilainen, V.O.Merckel, M.C.Falck, S.Ojala, P.J.Pohl, E.Wilmanns, M.Lappalainen, P.

(2002) J.Biol.Chem. 277: 43089-43095

  • DOI: 10.1074/jbc.M208225200

  • PubMed Abstract: 
  • Twinfilin is an evolutionarily conserved actin monomer-binding protein that regulates cytoskeletal dynamics in organisms from yeast to mammals. It is composed of two actin-depolymerization factor homology (ADF-H) domains that show approximately 20% s ...

    Twinfilin is an evolutionarily conserved actin monomer-binding protein that regulates cytoskeletal dynamics in organisms from yeast to mammals. It is composed of two actin-depolymerization factor homology (ADF-H) domains that show approximately 20% sequence identity to ADF/cofilin proteins. In contrast to ADF/cofilins, which bind both G-actin and F-actin and promote filament depolymerization, twinfilin interacts only with G-actin. To elucidate the molecular mechanisms of twinfilin-actin monomer interaction, we determined the crystal structure of the N-terminal ADF-H domain of twinfilin and mapped its actin-binding site by site-directed mutagenesis. This domain has similar overall structure to ADF/cofilins, and the regions important for actin monomer binding in ADF/cofilins are especially well conserved in twinfilin. Mutagenesis studies show that the N-terminal ADF-H domain of twinfilin and ADF/cofilins also interact with actin monomers through similar interfaces, although the binding surface is slightly extended in twinfilin. In contrast, the regions important for actin-filament interactions in ADF/cofilins are structurally different in twinfilin. This explains the differences in actin-interactions (monomer versus filament binding) between twinfilin and ADF/cofilins. Taken together, our data show that the ADF-H domain is a structurally conserved actin-binding motif and that relatively small structural differences at the actin interfaces of this domain are responsible for the functional variation between the different classes of ADF-H domain proteins.


    Related Citations: 
    • Mouse A6/twinfilin is an actin monomer-binding protein that localizes to the regions of rapid actin dynamics
      Vartiainen, M.,Ojala, P.J.,Auvinen, P.,Peranen, J.,Lappalainen, P.
      (2000) Mol.Cell.Biol. 20: 1772
    • Twinfilin Forms a Stable Complex with ADP-Actin Monomers Through its Carboxyl-Terminal ADF-H Domain
      Ojala, P.J.,Paavilainen, V.O.,Vartiainen, M.K.,Tuma, R.,Weeds, A.G.,Lappalainen, P.
      () TO BE PUBLISHED --: --


    Organizational Affiliation

    Program in Cellular Biotechnology, Institute of Biotechnology, P.O. Box 56, University of Helsinki, 00014 Helsinki, Finland.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
A6 gene product
A, B
142Mus musculusMutation(s): 0 
Gene Names: Twf1 (Ptk9)
Find proteins for Q91YR1 (Mus musculus)
Go to UniProtKB:  Q91YR1
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.232 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 47.544α = 90.00
b = 74.488β = 90.00
c = 76.946γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
SHARPphasing
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-11-13
    Type: Initial release
  • Version 1.1: 2008-04-28
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance