View source for 1fi5


==NMR STRUCTURE OF THE C TERMINAL DOMAIN OF CARDIAC TROPONIN C BOUND TO THE N TERMINAL DOMAIN OF CARDIAC TROPONIN I.==
<StructureSection load='1fi5' size='340' side='right'caption='[[1fi5]], [[NMR_Ensembles_of_Models | 20 NMR models]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1fi5]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Chick Chick]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=1ggs 1ggs]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1FI5 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1FI5 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1fi5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1fi5 OCA], [https://pdbe.org/1fi5 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1fi5 RCSB], [https://www.ebi.ac.uk/pdbsum/1fi5 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1fi5 ProSAT]</span></td></tr>
</table>
== Function ==
[[https://www.uniprot.org/uniprot/TNNC1_CHICK TNNC1_CHICK]] Troponin is the central regulatory protein of striated muscle contraction. Tn consists of three components: Tn-I which is the inhibitor of actomyosin ATPase, Tn-T which contains the binding site for tropomyosin and Tn-C. The binding of calcium to Tn-C abolishes the inhibitory action of Tn on actin filaments. 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/fi/1fi5_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1fi5 ConSurf].
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== Publication Abstract from PubMed ==
The N-terminal domain of cardiac troponin I (cTnI) comprising residues 33-80 and lacking the cardiac-specific amino terminus forms a stable binary complex with the C-terminal domain of cardiac troponin C (cTnC) comprising residues 81-161. We have utilized heteronuclear multidimensional NMR to assign the backbone and side-chain resonances of Ca2+-saturated cTnC(81-161) both free and bound to cTnI(33-80). No significant differences were observed between secondary structural elements determined for free and cTnI(33-80)-bound cTnC(81-161). We have determined solution structures of Ca2+-saturated cTnC(81-161) free and bound to cTnI(33-80). While the tertiary structure of cTnC(81-161) is qualitatively similar to that observed free in solution, the binding of cTnI(33-80) results mainly in an opening of the structure and movement of the loop region between helices F and G. Together, these movements provide the binding site for the N-terminal domain of cTnI. The putative binding site for cTnI(33-80) was determined by mapping amide proton and nitrogen chemical shift changes, induced by the binding of cTnI(33-80), onto the C-terminal cTnC structure. The binding interface for cTnI(33-80), as suggested from chemical shift changes, involves predominantly hydrophobic interactions located in the expanded hydrophobic pocket. The largest chemical shift changes were observed in the loop region connecting helices F and G. Inspection of available TnC sequences reveals that these residues are highly conserved, suggesting a common binding motif for the Ca2+/Mg2+-dependent interaction site in the TnC/TnI complex.

Solution structures of the C-terminal domain of cardiac troponin C free and bound to the N-terminal domain of cardiac troponin I.,Gasmi-Seabrook GM, Howarth JW, Finley N, Abusamhadneh E, Gaponenko V, Brito RM, Solaro RJ, Rosevear PR Biochemistry. 1999 Jun 29;38(26):8313-22. PMID:10387077<ref>PMID:10387077</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Troponin|Troponin]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Chick]]
[[Category: Large Structures]]
[[Category: Abusamhadneh, E]]
[[Category: Brito, R M]]
[[Category: Finley, N]]
[[Category: Gaponenko, V]]
[[Category: Gasmi-Seabrook, G M]]
[[Category: Howarth, J W]]
[[Category: Rosevear, P R]]
[[Category: Solaro, R J]]
[[Category: Calcium binding protein]]
[[Category: Cardiac]]
[[Category: Contractile protein]]
[[Category: Muscle protein]]
[[Category: Troponin c-troponin i interaction]]