6ANU

Cryo-EM structure of F-actin complexed with the beta-III-spectrin actin-binding domain


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 7.00 Å
  • Aggregation State: FILAMENT 
  • Reconstruction Method: HELICAL 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structural basis for high-affinity actin binding revealed by a beta-III-spectrin SCA5 missense mutation.

Avery, A.W.Fealey, M.E.Wang, F.Orlova, A.Thompson, A.R.Thomas, D.D.Hays, T.S.Egelman, E.H.

(2017) Nat Commun 8: 1350-1350

  • DOI: https://doi.org/10.1038/s41467-017-01367-w
  • Primary Citation of Related Structures:  
    6ANU

  • PubMed Abstract: 

    Spinocerebellar ataxia type 5 (SCA5) is a neurodegenerative disease caused by mutations in the cytoskeletal protein β-III-spectrin. Previously, a SCA5 mutation resulting in a leucine-to-proline substitution (L253P) in the actin-binding domain (ABD) was shown to cause a 1000-fold increase in actin-binding affinity. However, the structural basis for this increase is unknown. Here, we report a 6.9 Å cryo-EM structure of F-actin complexed with the L253P ABD. This structure, along with co-sedimentation and pulsed-EPR measurements, demonstrates that high-affinity binding caused by the CH2-localized mutation is due to opening of the two CH domains. This enables CH1 to bind actin aided by an unstructured N-terminal region that becomes α-helical upon binding. This helix is required for association with actin as truncation eliminates binding. Collectively, these results shed light on the mechanism by which β-III-spectrin, and likely similar actin-binding proteins, interact with actin, and how this mechanism can be perturbed to cause disease.


  • Organizational Affiliation

    Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, 55455, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Actin, cytoplasmic 1375Homo sapiensMutation(s): 0 
Gene Names: ACTB
UniProt & NIH Common Fund Data Resources
Find proteins for P60709 (Homo sapiens)
Explore P60709 
Go to UniProtKB:  P60709
PHAROS:  P60709
GTEx:  ENSG00000075624 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP60709
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Spectrin beta chain, non-erythrocytic 2284Homo sapiensMutation(s): 1 
Gene Names: SPTBN2KIAA0302SCA5
UniProt & NIH Common Fund Data Resources
Find proteins for O15020 (Homo sapiens)
Explore O15020 
Go to UniProtKB:  O15020
PHAROS:  O15020
GTEx:  ENSG00000173898 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO15020
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 7.00 Å
  • Aggregation State: FILAMENT 
  • Reconstruction Method: HELICAL 
EM Software:
TaskSoftware PackageVersion
RECONSTRUCTIONSPIDER
MODEL REFINEMENTPHENIX
MODEL REFINEMENTCoot

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM81303
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM44757
National Institutes of Health/National Institute on Aging (NIH/NIA)United StatesAG32961

Revision History  (Full details and data files)

  • Version 1.0: 2017-11-22
    Type: Initial release
  • Version 1.1: 2019-12-18
    Changes: Author supporting evidence
  • Version 1.2: 2024-03-13
    Changes: Data collection, Database references