PDBsum entry 1ozs

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protein metals Protein-protein interface(s) links
Structural protein PDB id
Jmol PyMol
Protein chains
73 a.a. *
20 a.a. *
_CA ×2
* Residue conservation analysis
PDB id:
Name: Structural protein
Title: C-domain of human cardiac troponin c in complex with the inhibitory region of human cardiac troponin i
Structure: Troponin c, slow skeletal and cardiac muscles. Chain: a. Synonym: tn-c. Engineered: yes. Troponin i, cardiac muscle. Chain: b. Synonym: cip. Engineered: yes
Source: Homo sapiens. Human. Organism_taxid: 9606. Gene: tnnc1 or tnnc. Expressed in: escherichia coli. Expression_system_taxid: 562. Gene: tnni3 or tnnc1.
NMR struc: 30 models
Authors: D.A.Lindhout,B.D.Sykes
Key ref:
D.A.Lindhout and B.D.Sykes (2003). Structure and dynamics of the C-domain of human cardiac troponin C in complex with the inhibitory region of human cardiac troponin I. J Biol Chem, 278, 27024-27034. PubMed id: 12732641 DOI: 10.1074/jbc.M302497200
09-Apr-03     Release date:   16-Sep-03    
Go to PROCHECK summary

Protein chain
Pfam   ArchSchema ?
P63316  (TNNC1_HUMAN) -  Troponin C, slow skeletal and cardiac muscles
161 a.a.
73 a.a.*
Protein chain
Pfam   ArchSchema ?
P19429  (TNNI3_HUMAN) -  Troponin I, cardiac muscle
210 a.a.
20 a.a.
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 2 residue positions (black crosses)

 Gene Ontology (GO) functional annotation 
  GO annot!
  Biochemical function     calcium ion binding     1 term  


DOI no: 10.1074/jbc.M302497200 J Biol Chem 278:27024-27034 (2003)
PubMed id: 12732641  
Structure and dynamics of the C-domain of human cardiac troponin C in complex with the inhibitory region of human cardiac troponin I.
D.A.Lindhout, B.D.Sykes.
Cardiac troponin C is the Ca2+-dependent switch for heart muscle contraction. Troponin C is associated with various other proteins including troponin I and troponin T. The interaction between the subunits within the troponin complex is of critical importance in understanding contractility. Following a Ca2+ signal to begin contraction, the inhibitory region of troponin I comprising residues Thr128-Arg147 relocates from its binding surface on actin to troponin C, triggering movement of troponin-tropomyosin within the thin filament and thereby freeing actin-binding site(s) for interactions with the myosin ATPase of the thick filament to generate the power stroke. The structure of calcium-saturated cardiac troponin C (C-domain) in complex with the inhibitory region of troponin I was determined using multinuclear and multidimensional nuclear magnetic resonance spectroscopy. The structure of this complex reveals that the inhibitory region adopts a helical conformation spanning residues Leu134-Lys139, with a novel orientation between the E- and H-helices of troponin C, which is largely stabilized by electrostatic interactions. By using isotope labeling, we have studied the dynamics of the protein and peptide in the binary complex. The structure of this inhibited complex provides a framework for understanding into interactions within the troponin complex upon heart contraction.
  Selected figure(s)  
Figure 2.
FIG. 2. A, stereo ensemble of the 30 lowest energy structures of cCTnC·2Ca^2^+ (blue) in complex with the inhibitory region (red) of cardiac troponin I-(128-147) (cIp), superimposition of cCTnC (Glu95-Glu155) backbone. Residues Ile^131-Lys139 are well ordered, whereas residues Arg140-Arg147 are flexible in the binary complex. B, ribbon diagram of the binary complex cCTnC·2Ca^2^+·cIp. The helical region of cIp encompasses residues Leu134-Lys139 (red) completing 1.5 turns of a helix is colored in red. N and C termini of each protein in the binary complex are as indicated, and all helices of cCTnC are defined. C, chemical shift surface map of cCTnC·2Ca^2^+·cIp as based upon the titration performed in Fig. 1A. Chemical shift changes are measured as (ppm) = ( N2 + H2)1/2, with areas of large chemical shift perturbation shown by the colored gradient. cIp peptide backbone is colored blue, with all heavy side chain atoms colored green. Stereo ensemble and ribbon diagram were generated using DINO (DINO: Visualizing Structural Biology (2002), and the chemical shift surface map was generated using Insight II version 98 (Accelrys Inc.).
Figure 3.
FIG. 3. A, electrostatic surface map of binary complex cCTnC·2Ca^2^+·cIp with acidic regions colored red and basic regions colored blue. Ribbon diagram of domain orientation is as shown. Selected residues within the complex are as labeled. B, 90 °C rotation of complex about the y axis. Surface maps generated using the programs GRASP (67) and RASTER3D (68). Ribbon diagrams generated using the program Insight II version 98 (Accelrys Inc.).
  The above figures are reprinted by permission from the ASBMB: J Biol Chem (2003, 278, 27024-27034) copyright 2003.  
  Figures were selected by an automated process.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
19542563 I.M.Robertson, M.X.Li, and B.D.Sykes (2009).
Solution structure of human cardiac troponin C in complex with the green tea polyphenol, (-)-epigallocatechin 3-gallate.
  J Biol Chem, 284, 23012-23023.
PDB code: 2kdh
19141534 N.J.Palpant, L.G.D'Alecy, and J.M.Metzger (2009).
Single histidine button in cardiac troponin I sustains heart performance in response to severe hypercapnic respiratory acidosis in vivo.
  FASEB J, 23, 1529-1540.  
18570382 I.M.Robertson, O.K.Baryshnikova, M.X.Li, and B.D.Sykes (2008).
Defining the binding site of levosimendan and its analogues in a regulatory cardiac troponin C-troponin I complex.
  Biochemistry, 47, 7485-7495.  
18162171 M.X.Li, I.M.Robertson, and B.D.Sykes (2008).
Interaction of cardiac troponin with cardiotonic drugs: a structural perspective.
  Biochem Biophys Res Commun, 369, 88-99.  
18398685 O.K.Baryshnikova, T.C.Williams, and B.D.Sykes (2008).
Internal pH indicators for biomolecular NMR.
  J Biomol NMR, 41, 5-7.  
16432210 M.Ikura, and J.B.Ames (2006).
Genetic polymorphism and protein conformational plasticity in the calmodulin superfamily: two ways to promote multifunctionality.
  Proc Natl Acad Sci U S A, 103, 1159-1164.  
16416046 J.C.Tardiff (2005).
Sarcomeric proteins and familial hypertrophic cardiomyopathy: linking mutations in structural proteins to complex cardiovascular phenotypes.
  Heart Fail Rev, 10, 237-248.  
15709952 T.Kobayashi, and R.J.Solaro (2005).
Calcium, thin filaments, and the integrative biology of cardiac contractility.
  Annu Rev Physiol, 67, 39-67.  
15711886 M.X.Li, X.Wang, and B.D.Sykes (2004).
Structural based insights into the role of troponin in cardiac muscle pathophysiology.
  J Muscle Res Cell Motil, 25, 559-579.  
12886291 B.D.Sykes (2003).
Pulling the calcium trigger.
  Nat Struct Biol, 10, 588-589.  
14661957 M.X.Li, X.Wang, D.A.Lindhout, N.Buscemi, J.E.Van Eyk, and B.D.Sykes (2003).
Phosphorylation and mutation of human cardiac troponin I deferentially destabilize the interaction of the functional regions of troponin I with troponin C.
  Biochemistry, 42, 14460-14468.  
The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time. Where a reference describes a PDB structure, the PDB code is shown on the right.