1J1E

Crystal structure of the 52kDa domain of human cardiac troponin in the Ca2+ saturated form


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.30 Å
  • R-Value Free: 0.308 
  • R-Value Work: 0.251 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Structure of the core domain of human cardiac troponin in the Ca2+-saturated form

Takeda, S.Yamashita, A.Maeda, K.Maeda, Y.

(2003) Nature 424: 35-41

  • DOI: https://doi.org/10.1038/nature01780
  • Primary Citation of Related Structures:  
    1J1D, 1J1E

  • PubMed Abstract: 

    Troponin is essential in Ca(2+) regulation of skeletal and cardiac muscle contraction. It consists of three subunits (TnT, TnC and TnI) and, together with tropomyosin, is located on the actin filament. Here we present crystal structures of the core domains (relative molecular mass of 46,000 and 52,000) of human cardiac troponin in the Ca(2+)-saturated form. Analysis of the four-molecule structures reveals that the core domain is further divided into structurally distinct subdomains that are connected by flexible linkers, making the entire molecule highly flexible. The alpha-helical coiled-coil formed between TnT and TnI is integrated in a rigid and asymmetric structure (about 80 angstrom long), the IT arm, which bridges putative tropomyosin-anchoring regions. The structures of the troponin ternary complex imply that Ca(2+) binding to the regulatory site of TnC removes the carboxy-terminal portion of TnI from actin, thereby altering the mobility and/or flexibility of troponin and tropomyosin on the actin filament.


  • Organizational Affiliation

    Laboratory for Structural Biochemistry, RIKEN Harima Institute at SPring-8, Mikazuki, Sayo, Hyogo, Japan. stakeda@ri.ncvc.go.jp


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Troponin C
A, D
161Homo sapiensMutation(s): 2 
UniProt & NIH Common Fund Data Resources
Find proteins for P63316 (Homo sapiens)
Explore P63316 
Go to UniProtKB:  P63316
GTEx:  ENSG00000114854 
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UniProt GroupP63316
Sequence Annotations
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  • Reference Sequence
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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Troponin T
B, E
106Homo sapiensMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for P45379 (Homo sapiens)
Explore P45379 
Go to UniProtKB:  P45379
GTEx:  ENSG00000118194 
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UniProt GroupP45379
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  • Reference Sequence
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Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
Troponin I
C, F
180Homo sapiensMutation(s): 3 
UniProt & NIH Common Fund Data Resources
Find proteins for P19429 (Homo sapiens)
Explore P19429 
Go to UniProtKB:  P19429
GTEx:  ENSG00000129991 
Entity Groups  
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UniProt GroupP19429
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.30 Å
  • R-Value Free: 0.308 
  • R-Value Work: 0.251 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 48.299α = 90
b = 169.506β = 102.38
c = 68.538γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
SHARPphasing
CNSrefinement

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-07-15
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2021-11-10
    Changes: Database references, Derived calculations
  • Version 1.4: 2023-10-25
    Changes: Data collection, Refinement description