1TNQ

STRUCTURES OF THE APO AND CALCIUM TROPONIN-C REGULATORY DOMAINS: THE MUSCLE CONTRACTION SWITCH

• PDB DOI: https://doi.org/10.2210/pdb1TNQ/pdb

• Classification: CALCIUM-BINDING PROTEIN
• Organism(s): Gallus gallus
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 1995-07-07 Released: 1995-10-15 
• Deposition Author(s): Gagne, S.M., Sykes, B.D.

---

Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Submitted: 40 

Literature

Structures of the troponin C regulatory domains in the apo and calcium-saturated states.

Gagne, S.M., Tsuda, S., Li, M.X., Smillie, L.B., Sykes, B.D.

(1995) Nat Struct Biol 2: 784-789

• PubMed: 7552750 
• DOI: https://doi.org/10.1038/nsb0995-784
• Primary Citation of Related Structures:  
  1TNP, 1TNQ


• PubMed Abstract: 
  

  Regulation of contraction in skeletal muscle occurs through calcium binding to the protein troponin C. The solution structures of the regulatory domain of apo and calcium-loaded troponin C have been determined by multinuclear, multidimensional nuclear magnetic resonance techniques. The structural transition in the regulatory domain of troponin C on calcium binding involves an opening of the structure through large changes in interhelical angles. This leads to the increased exposure of an extensive hydrophobic patch, an event that triggers skeletal muscle contraction.

---

Organizational Affiliation: 

Department of Biochemistry, University of Alberta, Edmonton, Canada.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 10.06 kDa 
• Atom Count: 695 
• Modelled Residue Count: 90 
• Deposited Residue Count: 90 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
TROPONIN-C	A	90	Gallus gallus	Mutation(s): 0  Gene Names: NTNC
UniProt
Find proteins for P02588 (Gallus gallus) Explore P02588  Go to UniProtKB:  P02588

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
CA	B [auth A], C [auth A]	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Submitted: 40 

Structure Validation

Entry History 

Deposition Data

• Released Date: 1995-10-15 
Deposition Author(s): Gagne, S.M., Sykes, B.D.

Revision History  

• Version 1.0: 1995-10-15
  Type: Initial release
  
• Version 1.1: 2008-03-03
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2022-03-02
  Changes: Database references, Derived calculations, Other
• Version 1.4: 2024-05-22
  Changes: Data collection