1SMG | pdb_00001smg

CALCIUM-BOUND E41A MUTANT OF THE N-DOMAIN OF CHICKEN TROPONIN C, NMR, 40 STRUCTURES

• PDB DOI: https://doi.org/10.2210/pdb1SMG/pdb

• Classification: CALCIUM-BINDING PROTEIN
• Organism(s): Gallus gallus
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 1997-02-04 Released: 1997-08-12 
• Deposition Author(s): Gagne, S.M., Li, M.X., Sykes, B.D.

---

Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 50 
• Conformers Submitted: 40 
• Selection Criteria: LOWEST TOTAL ENERGY 

Literature

Mechanism of direct coupling between binding and induced structural change in regulatory calcium binding proteins.

Gagne, S.M., Li, M.X., Sykes, B.D.

(1997) Biochemistry 36: 4386-4392

• PubMed: 9109645 
• DOI: https://doi.org/10.1021/bi963076+
• Primary Citation Related Structures: 
  1SMG


• PubMed Abstract: 
  

  The structural transition in troponin C induced by the binding of two calcium ions involves an "opening" of the structure, an event that triggers skeletal muscle contraction. We have solved the solution structure of a mutant (E41A) of the regulatory domain of skeletal troponin C wherein one bidentate ligand to the calcium in site I is missing. This structure remains "closed" upon calcium binding, indicating that the linkage between calcium binding and the induced conformational change has been broken. This provides a snapshot of skeletal troponin C between the off and on state and thereby valuable insight into the mechanism of regulation within skeletal TnC. Although several factors contribute to the triggering mechanism, the opening of the troponin C structure is ultimately dependent on one amino acid, Glu41. Insights into the structure of cardiac troponin C can also be derived from this skeletal mutant.

---

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: 9.97 kDa 
• Atom Count: 690 
• Modeled 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): 1
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]	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 50 
• Conformers Submitted: 40 
• Selection Criteria: LOWEST TOTAL ENERGY 

Structure Validation

Entry History 

Deposition Data

• Released Date: 1997-08-12 
Deposition Author(s): Gagne, S.M., Li, M.X., Sykes, B.D.

Revision History  

• Version 1.0: 1997-08-12
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2021-11-03
  Changes: Database references, Derived calculations, Other
• Version 1.4: 2024-05-22
  Changes: Data collection