View source for 7sc2


==CRYSTAL STRUCTURE OF THE N-DOMAIN OF CARDIAC MUSCLE TROPONIN C TETHERED TO THE SWITCH REGION OF CARDIAC MUSCLE TROPONIN I (TETRAGONAL FORM)==
<StructureSection load='7sc2' size='340' side='right'caption='[[7sc2]], [[Resolution|resolution]] 1.81&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7sc2]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7SC2 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7SC2 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.814&#8491;</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=7sc2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7sc2 OCA], [https://pdbe.org/7sc2 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7sc2 RCSB], [https://www.ebi.ac.uk/pdbsum/7sc2 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7sc2 ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/TNNC1_HUMAN TNNC1_HUMAN] Defects in TNNC1 are the cause of cardiomyopathy dilated type 1Z (CMD1Z) [MIM:[https://omim.org/entry/611879 611879]. Dilated cardiomyopathy is a disorder characterized by ventricular dilation and impaired systolic function, resulting in congestive heart failure and arrhythmia. Patients are at risk of premature death.<ref>PMID:15542288</ref>   Defects in TNNC1 are the cause of familial hypertrophic cardiomyopathy type 13 (CMH13) [MIM:[https://omim.org/entry/613243 613243]. A hereditary heart disorder characterized by ventricular hypertrophy, which is usually asymmetric and often involves the interventricular septum. The symptoms include dyspnea, syncope, collapse, palpitations, and chest pain. They can be readily provoked by exercise. The disorder has inter- and intrafamilial variability ranging from benign to malignant forms with high risk of cardiac failure and sudden cardiac death.<ref>PMID:11385718</ref> <ref>PMID:16302972</ref> <ref>PMID:18572189</ref> <ref>PMID:19439414</ref> [https://www.uniprot.org/uniprot/TNNI3_HUMAN TNNI3_HUMAN] Defects in TNNI3 are the cause of familial hypertrophic cardiomyopathy type 7 (CMH7) [MIM:[https://omim.org/entry/613690 613690]. Familial hypertrophic cardiomyopathy is a hereditary heart disorder characterized by ventricular hypertrophy, which is usually asymmetric and often involves the interventricular septum. The symptoms include dyspnea, syncope, collapse, palpitations, and chest pain. They can be readily provoked by exercise. The disorder has inter- and intrafamilial variability ranging from benign to malignant forms with high risk of cardiac failure and sudden cardiac death.<ref>PMID:9241277</ref> <ref>PMID:11815426</ref> <ref>PMID:12707239</ref> <ref>PMID:12974739</ref> <ref>PMID:16199542</ref>   Defects in TNNI3 are the cause of familial restrictive cardiomyopathy type 1 (RCM1) [MIM:[https://omim.org/entry/115210 115210]. RCM1 is a heart muscle disorder characterized by impaired filling of the ventricles with reduced diastolic volume, in the presence of normal or near normal wall thickness and systolic function.<ref>PMID:12531876</ref>   Defects in TNNI3 are the cause of cardiomyopathy dilated type 2A (CMD2A) [MIM:[https://omim.org/entry/611880 611880]. Dilated cardiomyopathy is a disorder characterized by ventricular dilation and impaired systolic function, resulting in congestive heart failure and arrhythmia. Patients are at risk of premature death.<ref>PMID:15070570</ref>   Defects in TNNI3 are the cause of cardiomyopathy dilated type 1FF (CMD1FF) [MIM:[https://omim.org/entry/613286 613286]. Dilated cardiomyopathy is a disorder characterized by ventricular dilation and impaired systolic function, resulting in congestive heart failure and arrhythmia. Patients are at risk of premature death.
== Function ==
[https://www.uniprot.org/uniprot/TNNC1_HUMAN TNNC1_HUMAN] 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.[https://www.uniprot.org/uniprot/TNNI3_HUMAN TNNI3_HUMAN] Troponin I is the inhibitory subunit of troponin, the thin filament regulatory complex which confers calcium-sensitivity to striated muscle actomyosin ATPase activity.
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== Publication Abstract from PubMed ==
The X-ray crystal structure of a human cardiac muscle troponin C/troponin I chimera has been determined in two different crystal forms and shows a conformation of the complex that differs from that previously observed by NMR. The chimera consists of the N-terminal domain of troponin C (cTnC; residues 1-80) fused to the switch region of troponin I (cTnI; residues 138-162). In both crystal forms, the cTnI residues form a six-turn alpha-helix that lays across the hydrophobic groove of an adjacent cTnC molecule in the crystal structure. In contrast to previous models, the cTnI helix runs in a parallel direction relative to the cTnC groove and completely blocks the calcium desensitizer binding site of the cTnC-cTnI interface.

X-ray structure of a human cardiac muscle troponin C/troponin I chimera in two crystal forms.,Yan C, Sack JS Acta Crystallogr F Struct Biol Commun. 2022 Jan 1;78(Pt 1):17-24. doi:, 10.1107/S2053230X21012395. Epub 2022 Jan 1. PMID:34981771<ref>PMID:34981771</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7sc2" style="background-color:#fffaf0;"></div>

==See Also==
*[[Troponin 3D structures|Troponin 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Sack JS]]