5KHT

Crystal structure of the N-terminal fragment of tropomyosin isoform Tpm1.1 at 1.5 A resolution


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.4964 Å
  • R-Value Free: 0.249 
  • R-Value Work: 0.205 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural destabilization of tropomyosin induced by the cardiomyopathy-linked mutation R21H.

Ly, T.Krieger, I.Tolkatchev, D.Krone, C.Moural, T.Samatey, F.A.Kang, C.Kostyukova, A.S.

(2018) Protein Sci. 27: 498-508

  • DOI: 10.1002/pro.3341

  • PubMed Abstract: 
  • The missense mutation R21H in striated muscle tropomyosin is associated with hypertrophic cardiomyopathy, a genetic cardiac disease and a leading cause of sudden cardiac death in young people. Tropomyosin adopts conformation of a coiled coil which is ...

    The missense mutation R21H in striated muscle tropomyosin is associated with hypertrophic cardiomyopathy, a genetic cardiac disease and a leading cause of sudden cardiac death in young people. Tropomyosin adopts conformation of a coiled coil which is critical for regulation of muscle contraction. In this study, we investigated the effects of the R21H mutation on the coiled-coil structure of tropomyosin and its interactions with its binding partners, tropomodulin and leiomodin. Using circular dichroism and isothermal titration calorimetry, we found that the mutation profoundly destabilized the structural integrity of αTM1a 1-28 Zip, a chimeric peptide containing the first 28 residues of tropomyosin. The mutated αTM1a 1-28 Zip was still able to interact with tropomodulin and leiomodin. However, the mutation resulted in a ∼30-fold decrease of αTM1a 1-28 Zip's binding affinity to leiomodin. We used a crystal structure of αTM1a 1-28 Zip that we solved at 1.5 Å resolution to study the mutation's effect in silico by means of molecular dynamics simulation. The simulation data indicated that while the mutation disrupted αTM1a 1-28 Zip's coiled-coil structure, most notably from residue Ala18 to residue His31, it may not affect the N-terminal end of tropomyosin. The drastic decrease of αTM1a 1-28 Zip's affinity to leiomodin caused by the mutation may lead to changes in the dynamics at the pointed end of thin filaments. Therefore, the R21H mutation is likely interfering with the regulation of the normal thin filament length essential for proper muscle contraction.


    Organizational Affiliation

    Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington.,Trans-Membrane Trafficking Unit, Okinawa Institute of Science and Technology, Okinawa, Japan.,Department of Chemistry, Washington State University, Pullman, Washington.,Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Tropomyosin alpha-1 chain,General control protein GCN4
A, B, C, D
47Homo sapiensSaccharomyces cerevisiae (strain ATCC 204508 / S288c)
This entity is chimeric
Mutation(s): 0 
Gene Names: TPM1 (C15orf13, TMSA), GCN4 (AAS3, ARG9)
Find proteins for P09493 (Homo sapiens)
Go to Gene View: TPM1
Go to UniProtKB:  P09493
Find proteins for P03069 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Go to UniProtKB:  P03069
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PEG
Query on PEG

Download SDF File 
Download CCD File 
B, C, D
DI(HYDROXYETHYL)ETHER
C4 H10 O3
MTHSVFCYNBDYFN-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.4964 Å
  • R-Value Free: 0.249 
  • R-Value Work: 0.205 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 35.970α = 65.21
b = 36.470β = 74.71
c = 36.710γ = 78.98
Software Package:
Software NamePurpose
XDSdata reduction
PHENIXrefinement
PHASERphasing
XSCALEdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2017-06-21
    Type: Initial release
  • Version 1.1: 2017-09-06
    Type: Author supporting evidence
  • Version 1.2: 2019-01-02
    Type: Data collection, Database references