PDBsum entry 1npq

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protein metals Protein-protein interface(s) links
Structural protein PDB id
Protein chains
90 a.a. *
17 a.a. *
_CA ×2
* Residue conservation analysis
PDB id:
Name: Structural protein
Title: Structure of a rhodamine-labeled n-domain troponin c mutant (ca2+ saturated) in complex with skeletal troponin i 115- 131
Structure: Troponin c. Chain: a. Fragment: tnc, residues 1-90. Synonym: troponin c, skeletal muscle. Engineered: yes. Mutation: yes. Troponin i. Chain: b. Fragment: switch peptide, residues 115-131.
Source: Gallus gallus. Chicken. Organism_taxid: 9031. Gene: tnnc2. Expressed in: escherichia coli. Expression_system_taxid: 562. Synthetic: yes. Other_details: this sequence occurs naturally in oryctolagus cuniculus (rabit)
NMR struc: 21 models
Authors: P.Mercier,R.E.Ferguson,M.Irving,J.E.T.Corrie,D.R.Trentham, B.D.Sykes
Key ref:
P.Mercier et al. (2003). NMR structure of a bifunctional rhodamine labeled N-domain of troponin C complexed with the regulatory "switch" peptide from troponin I: implications for in situ fluorescence studies in muscle fibers. Biochemistry, 42, 4333-4348. PubMed id: 12693929 DOI: 10.1021/bi027041n
18-Jan-03     Release date:   29-Apr-03    
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Protein chain
Pfam   ArchSchema ?
P02588  (TNNC2_CHICK) -  Troponin C, skeletal muscle
163 a.a.
90 a.a.*
Protein chain
Pfam   ArchSchema ?
P02643  (TNNI2_RABIT) -  Troponin I, fast skeletal muscle
182 a.a.
17 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 3 residue positions (black crosses)

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


DOI no: 10.1021/bi027041n Biochemistry 42:4333-4348 (2003)
PubMed id: 12693929  
NMR structure of a bifunctional rhodamine labeled N-domain of troponin C complexed with the regulatory "switch" peptide from troponin I: implications for in situ fluorescence studies in muscle fibers.
P.Mercier, R.E.Ferguson, M.Irving, J.E.Corrie, D.R.Trentham, B.D.Sykes.
The structure of the calcium-saturated regulatory domain of skeletal troponin C (sNTnC) complexed with the switch peptide comprising residues 115-131 of troponin I (TnI), and with a bifunctional rhodamine fluorescent label attached to residues 56 (E56C) and 63 (E63C) on the C helix of sNTnC, has been determined using nuclear magnetic resonance (NMR) spectroscopy. The structure shows that the integrity of the C helix is not altered by the E(56,63)C mutations or by the presence of the bifunctional rhodamine and that the label does not interact with the hydrophobic cleft of sNTnC. Moreover, the overall fold of the protein and the position of the TnI peptide are similar to those observed previously with related cardiac NTnC complexes with residues 147-163 of cardiac TnI [Li et al. (1999) Biochemistry 38, 8289-8298] and including the drug bepridil [Wang et al. (2002) J. Biol. Chem. 277, 31124-31133]. The degree of opening of the structure is reduced as compared to that of calcium-saturated sNTnC in the absence of the switch peptide [Gagné et al. (1995) Nat. Struct. Biol. 2, 784-789]. The switch peptide is bound in a shallow and complementary hydrophobic surface cleft largely defined by helices A and B and also has key ionic interactions with sNTnC. These results show that bifunctional rhodamine probes can be attached to surface helices via suitable pairs of solvent-accessible residues that have been mutated to cysteines, without altering the conformation of the labeled domain. A set of such probes can be used to determine the orientation and motion of the target domain in the cellular environment [Corrie et al. (1999) Nature 400, 425-430; Ferguson et al. (2003) Mol. Cell 11(4), in press].

Literature references that cite this PDB file's key reference

  PubMed id Reference
18621839 A.C.Knowles, R.E.Ferguson, B.D.Brandmeier, Y.B.Sun, D.R.Trentham, and M.Irving (2008).
Orientation of the essential light chain region of myosin in relaxed, active, and rigor muscle.
  Biophys J, 95, 3882-3891.  
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.  
17483167 O.Julien, Y.B.Sun, A.C.Knowles, B.D.Brandmeier, R.E.Dale, D.R.Trentham, J.E.Corrie, B.D.Sykes, and M.Irving (2007).
Toward protein structure in situ: comparison of two bifunctional rhodamine adducts of troponin C.
  Biophys J, 93, 1008-1020.  
17101992 Y.B.Sun, B.Brandmeier, and M.Irving (2006).
Structural changes in troponin in response to Ca2+ and myosin binding to thin filaments during activation of skeletal muscle.
  Proc Natl Acad Sci U S A, 103, 17771-17776.  
15784741 M.V.Vinogradova, D.B.Stone, G.G.Malanina, C.Karatzaferi, R.Cooke, R.A.Mendelson, and R.J.Fletterick (2005).
Ca(2+)-regulated structural changes in troponin.
  Proc Natl Acad Sci U S A, 102, 5038-5043.
PDB codes: 1ytz 1yv0
15826946 T.M.Blumenschein, D.B.Stone, R.J.Fletterick, R.A.Mendelson, and B.D.Sykes (2005).
Calcium-dependent changes in the flexibility of the regulatory domain of troponin C in the troponin complex.
  J Biol Chem, 280, 21924-21932.  
14970231 J.P.Davis, J.A.Rall, C.Alionte, and S.B.Tikunova (2004).
Mutations of hydrophobic residues in the N-terminal domain of troponin C affect calcium binding and exchange with the troponin C-troponin I96-148 complex and muscle force production.
  J Biol Chem, 279, 17348-17360.  
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.  
12732641 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.
PDB code: 1ozs
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