1J1D

Crystal structure of the 46kDa domain of human cardiac troponin in the Ca2+ saturated form


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.61 Å
  • R-Value Free: 0.298 
  • R-Value Work: 0.264 

wwPDB Validation 3D Report Full Report


This is version 1.2 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: 10.1038/nature01780
  • Primary Citation of Related Structures:  

  • 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 d ...

    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.


    Related Citations: 
    • Structural and functional domains of the troponin complex revealed by limited digestion
      Takeda, S.,Kobayashi, T.,Taniguchi, H.,Hayashi, H.,Maeda, Y.
      (1997) Eur.J.Biochem. 246: 611
    • Crystal structure of troponin C in complex with troponin I fragment at 2.3-A resolution
      Vassylyev, D.G.,Takeda, S.,Wakatsuki, S.,Maeda, K.,Maeda, Y.
      (1998) Proc.Natl.Acad.Sci.USA 95: 4847


    Organizational Affiliation

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




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Troponin C
A, D
161Homo sapiensMutation(s): 2 
Gene Names: TNNC1 (TNNC)
Find proteins for P63316 (Homo sapiens)
Go to Gene View: TNNC1
Go to UniProtKB:  P63316
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Troponin T
B, E
106Homo sapiensMutation(s): 0 
Gene Names: TNNT2
Find proteins for P45379 (Homo sapiens)
Go to Gene View: TNNT2
Go to UniProtKB:  P45379
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
Troponin I
C, F
133Homo sapiensMutation(s): 3 
Gene Names: TNNI3 (TNNC1)
Find proteins for P19429 (Homo sapiens)
Go to Gene View: TNNI3
Go to UniProtKB:  P19429
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
A, D
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.61 Å
  • R-Value Free: 0.298 
  • R-Value Work: 0.264 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 42.346α = 90.00
b = 167.860β = 101.35
c = 69.707γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
CNSrefinement
DENZOdata reduction
SHARPphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-07-15
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance