Crystal Structure of Human Filamin B Actin Binding Domain with 1st Filamin Repeat

Experimental Data Snapshot

  • Resolution: 2.05 Å
  • R-Value Free: 0.219 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.185 

Starting Model: experimental
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Crystal Structure of the Filamin N-Terminal Region Reveals a Hinge between the Actin Binding and First Repeat Domains

Sawyer, G.M.Sutherland-Smith, A.J.

(2012) J Mol Biol 424: 240

  • DOI: https://doi.org/10.1016/j.jmb.2012.09.016
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The filamin proteins cross-link F-actin and interact with protein partners to integrate both extracellular and intracellular signalling events with the cytoskeleton and to provide mechanoprotection and sensing to cells. The filamins are large, flexible, multi-domain homodimers with the interactions between domains important for protein function. The crystal structure of the N-terminal region of filamin B, containing the actin binding domain (ABD) and the first filamin repeat (FR1) domain, reveals an extended two-domain conformation with no interaction between the ABD and FR1 other than the connecting linker region. The two FLNB347 structures in the crystallographic asymmetric unit exhibit differing relative domain orientations providing the first high-resolution structural characterisation of a filamin inter-domain conformational change. The structure reveals a new hinge in the linker region between ABD and FR1 that is ideally positioned to orient the ABD for actin binding and adds to the previously described hinge regions, hinge 1 (between repeats 15 and 16) and hinge 2 (repeats 23 and 24), providing an additional mechanism by which filamin can exhibit inter-domain flexibility. The extended structure, with the absence of interactions between the domains, implies that any conformational rearrangements required for actin binding by the ABD, as observed for homologous proteins, can freely occur without being influenced by FR1. The ABD retains its previously observed compact conformation. FR1 exhibits a filamin immunoglobulin-like domain fold with a closed C-D β-strand groove, in contrast to filamin repeats that bind protein partners with this region of the domain surface.

  • Organizational Affiliation

    Institute of Molecular Biosciences, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
347Homo sapiensMutation(s): 1 
UniProt & NIH Common Fund Data Resources
Find proteins for O75369 (Homo sapiens)
Explore O75369 
Go to UniProtKB:  O75369
GTEx:  ENSG00000136068 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO75369
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.05 Å
  • R-Value Free: 0.219 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.185 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 72.18α = 90
b = 69.69β = 111.1
c = 73.46γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-10-10
    Type: Initial release
  • Version 1.1: 2012-10-17
    Changes: Atomic model, Database references, Other
  • Version 1.2: 2012-11-28
    Changes: Database references
  • Version 1.3: 2023-12-20
    Changes: Data collection, Database references, Other, Refinement description