4PKI

Complex of ATP-actin With the C-terminal Actin-Binding Domain of Tropomodulin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.201 
  • R-Value Work: 0.168 
  • R-Value Observed: 0.170 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.4 of the entry. See complete history


Literature

Actin cytoskeleton. Mechanism of actin filament pointed-end capping by tropomodulin.

Rao, J.N.Madasu, Y.Dominguez, R.

(2014) Science 345: 463-467

  • DOI: https://doi.org/10.1126/science.1256159
  • Primary Citation of Related Structures:  
    4PKG, 4PKH, 4PKI

  • PubMed Abstract: 

    Proteins that cap the ends of the actin filament are essential regulators of cytoskeleton dynamics. Whereas several proteins cap the rapidly growing barbed end, tropomodulin (Tmod) is the only protein known to cap the slowly growing pointed end. The lack of structural information severely limits our understanding of Tmod's capping mechanism. We describe crystal structures of actin complexes with the unstructured amino-terminal and the leucine-rich repeat carboxy-terminal domains of Tmod. The structures and biochemical analysis of structure-inspired mutants showed that one Tmod molecule interacts with three actin subunits at the pointed end, while also contacting two tropomyosin molecules on each side of the filament. We found that Tmod achieves high-affinity binding through several discrete low-affinity interactions, which suggests a mechanism for controlled subunit exchange at the pointed end.


  • Organizational Affiliation

    Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Actin, alpha skeletal muscle377Oryctolagus cuniculusMutation(s): 0 
EC: 3.6.4
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
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Gelsolin,Tropomodulin-1 chimeraB [auth G]324Homo sapiensMutation(s): 0 
Gene Names: GSNTMOD1D9S57ETMOD
UniProt & NIH Common Fund Data Resources
Find proteins for P28289 (Homo sapiens)
Explore P28289 
Go to UniProtKB:  P28289
PHAROS:  P28289
GTEx:  ENSG00000136842 
Find proteins for P06396 (Homo sapiens)
Explore P06396 
Go to UniProtKB:  P06396
PHAROS:  P06396
GTEx:  ENSG00000148180 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupsP28289P06396
Sequence Annotations
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  • Reference Sequence
Small Molecules
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.201 
  • R-Value Work: 0.168 
  • R-Value Observed: 0.170 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 69.393α = 90
b = 81.211β = 90
c = 170.708γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data scaling
Cootmodel building

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesR01 GM073791

Revision History  (Full details and data files)

  • Version 1.0: 2014-07-30
    Type: Initial release
  • Version 1.1: 2014-08-06
    Changes: Database references
  • Version 1.2: 2017-09-06
    Changes: Advisory, Author supporting evidence, Database references, Derived calculations, Other, Source and taxonomy
  • Version 1.3: 2019-12-25
    Changes: Author supporting evidence
  • Version 1.4: 2023-09-27
    Changes: Data collection, Database references, Derived calculations, Refinement description