6UBY

Isolated cofilin bound to an actin filament


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 7.50 Å
  • Aggregation State: HELICAL ARRAY 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structures of cofilin-induced structural changes reveal local and asymmetric perturbations of actin filaments.

Huehn, A.R.Bibeau, J.P.Schramm, A.C.Cao, W.De La Cruz, E.M.Sindelar, C.V.

(2020) Proc Natl Acad Sci U S A 117: 1478-1484

  • DOI: 10.1073/pnas.1915987117
  • Primary Citation of Related Structures:  
    6UBY, 6UC0, 6UC4, 6VAO, 6VAU

  • PubMed Abstract: 
  • Members of the cofilin/ADF family of proteins sever actin filaments, increasing the number of filament ends available for polymerization or depolymerization. Cofilin binds actin filaments with positive cooperativity, forming clusters of contiguously bound cofilin along the filament lattice ...

    Members of the cofilin/ADF family of proteins sever actin filaments, increasing the number of filament ends available for polymerization or depolymerization. Cofilin binds actin filaments with positive cooperativity, forming clusters of contiguously bound cofilin along the filament lattice. Filament severing occurs preferentially at boundaries between bare and cofilin-decorated (cofilactin) segments and is biased at 1 side of a cluster. A molecular understanding of cooperative binding and filament severing has been impeded by a lack of structural data describing boundaries. Here, we apply methods for analyzing filament cryo-electron microscopy (cryo-EM) data at the single subunit level to directly investigate the structure of boundaries within partially decorated cofilactin filaments. Subnanometer resolution maps of isolated, bound cofilin molecules and an actin-cofilactin boundary indicate that cofilin-induced actin conformational changes are local and limited to subunits directly contacting bound cofilin. An isolated, bound cofilin compromises longitudinal filament contacts of 1 protofilament, consistent with a single cofilin having filament-severing activity. An individual, bound phosphomimetic (S3D) cofilin with weak severing activity adopts a unique binding mode that does not perturb actin structure. Cofilin clusters disrupt both protofilaments, consistent with a higher severing activity at boundaries compared to single cofilin. Comparison of these structures indicates that this disruption is substantially greater at pointed end sides of cofilactin clusters than at the barbed end. These structures, with the distribution of bound cofilin clusters, suggest that maximum binding cooperativity is achieved when 2 cofilins occupy adjacent sites. These results reveal the structural origins of cooperative cofilin binding and actin filament severing.


    Organizational Affiliation

    Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520 enrique.delacruz@yale.edu charles.sindelar@yale.edu.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Actin, alpha skeletal muscle
A, B, C, D, E, F, G, H
A, B, C, D, E, F, G, H
377Oryctolagus cuniculusMutation(s): 0 
Gene Names: ACTA1ACTA
UniProt
Find proteins for P68135 (Oryctolagus cuniculus)
Explore P68135 
Go to UniProtKB:  P68135
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP68135
Protein Feature View
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  • Reference Sequence
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Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Cofilin-1I166Homo sapiensMutation(s): 0 
Gene Names: CFL1CFL
UniProt & NIH Common Fund Data Resources
Find proteins for P23528 (Homo sapiens)
Explore P23528 
Go to UniProtKB:  P23528
PHAROS:  P23528
GTEx:  ENSG00000172757 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP23528
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 7.50 Å
  • Aggregation State: HELICAL ARRAY 
  • Reconstruction Method: SINGLE PARTICLE 

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM097348
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM110533001

Revision History  (Full details and data files)

  • Version 1.0: 2020-01-01
    Type: Initial release
  • Version 1.1: 2020-01-15
    Changes: Database references
  • Version 1.2: 2020-02-05
    Changes: Database references