1PON

SITE III-SITE IV TROPONIN C HETERODIMER, NMR


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Submitted: 42 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

NMR solution structure of a synthetic troponin C heterodimeric domain.

Shaw, G.S.Sykes, B.D.

(1996) Biochemistry 35: 7429-7438

  • DOI: 10.1021/bi9528006

  • PubMed Abstract: 
  • The C-terminal domain from the muscle protein troponin C (TnC) comprises two helix-loop-helix calcium-binding sites (residues 90-162). The assembly of these two sites is governed by calcium binding enabling a synthetic C-terminal domain to be prefere ...

    The C-terminal domain from the muscle protein troponin C (TnC) comprises two helix-loop-helix calcium-binding sites (residues 90-162). The assembly of these two sites is governed by calcium binding enabling a synthetic C-terminal domain to be preferentially and stoichiometrically assembled from two synthetic peptides (residues 93-126, SCIII, and 129-162, SCIV) in the presence of calcium only. It is therefore of great interest to know how closely the structure of this heterodimeric domain is to the intact protein domain. Analysis of such a structure has important implications in protein engineering and in understanding the stability of calcium-binding proteins in terms of biological function. The solution structure of this heterodimeric protein was determined by 1H NMR spectroscopy using 802 NOE derived distance restraints and 23 phi and 22 chi angle restraints. Distance geometry-simulated annealing calculations yielded a family of 42 converged structures (rmsd 0.86 +/- 0.17 A) showing an arrangement of four alpha-helices similar in fold to the C-terminal of troponin C. The dimer interface has several important interactions between helix pairs E/H and F/G responsible for the association of the two peptides. However, neither the peptide complex nor the solution NMR structure of TnC pack as tightly as that observed in the TnC X-ray structure. The interhelical distance between the F/G helix is about 1.4 A greater in solution than in the crystal. A comparison of the exposed surface area of the hydrophobic residues in the SCIII/SCIV heterodimer revealed that residues 1104, Y112, and 1121 are more exposed than in the previously determined solution structure of the SCIII homodimer. These residues are important for the interaction with the inhibitory region of TnI and provide evidence for their involvement in the regulation of muscle contraction.


    Related Citations: 
    • Relative Stabilities of Synthetic Peptide Homo-and Heterodimeric Troponin-C Domains Journal Title: Protein Science
      Shaw, G.S.,Hodges, R.S.,Kay, C.M.,Sykes, B.D.
      () TO BE PUBLISHED --: --


    Organizational Affiliation

    Department of Biochemistry & McLaughlin Macromolecular Structure Facility, University of Western Ontario, London, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
TROPONIN C
A
36Gallus gallusGene Names: TNNC2
Find proteins for P02588 (Gallus gallus)
Go to Gene View: TNNC2
Go to UniProtKB:  P02588
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
TROPONIN C
B
36Gallus gallusGene Names: TNNC2
Find proteins for P02588 (Gallus gallus)
Go to Gene View: TNNC2
Go to UniProtKB:  P02588
Small Molecules
Modified Residues  2 Unique
IDChainsTypeFormula2D DiagramParent
NH2
Query on NH2
A, B
NON-POLYMERH2 N

--

ACE
Query on ACE
A, B
NON-POLYMERC2 H4 O

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Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Submitted: 42 
  • Olderado: 1PON Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1996-11-08
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance