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 1.1 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: 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) w ...

    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 Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, 22908, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Actin, cytoplasmic 1ABCDEF375Homo sapiensMutation(s): 0 
Gene Names: ACTB
Find proteins for P60709 (Homo sapiens)
Explore P60709 
Go to UniProtKB:  P60709
NIH Common Fund Data Resources
PHAROS  P60709
Protein Feature View
Expand
 ( Mouse scroll to zoom / Hold left click to move )
  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Spectrin beta chain, non-erythrocytic 2abcdef284Homo sapiensMutation(s): 1 
Gene Names: SPTBN2KIAA0302SCA5
Find proteins for O15020 (Homo sapiens)
Explore O15020 
Go to UniProtKB:  O15020
NIH Common Fund Data Resources
PHAROS  O15020
Protein Feature View
Expand
 ( Mouse scroll to zoom / Hold left click to move )
  • Reference Sequence
Experimental Data & Validation

Experimental Data

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

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 

  • Version 1.0: 2017-11-22
    Type: Initial release
  • Version 1.1: 2019-12-18
    Changes: Author supporting evidence