2mzp
From Proteopedia
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| - | ''' | + | ==Structure and dynamics of the acidosis-resistant a162H mutant of the switch region of troponin I bound to the regulatory domain of troponin C== |
| + | <StructureSection load='2mzp' size='340' side='right' caption='[[2mzp]], [[NMR_Ensembles_of_Models | 20 NMR models]]' scene=''> | ||
| + | == Structural highlights == | ||
| + | <table><tr><td colspan='2'>[[2mzp]] is a 2 chain structure. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2MZP OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2MZP FirstGlance]. <br> | ||
| + | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><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'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2mzp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2mzp OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2mzp RCSB], [http://www.ebi.ac.uk/pdbsum/2mzp PDBsum]</span></td></tr> | ||
| + | </table> | ||
| + | == Disease == | ||
| + | [[http://www.uniprot.org/uniprot/TNNC1_HUMAN TNNC1_HUMAN]] Defects in TNNC1 are the cause of cardiomyopathy dilated type 1Z (CMD1Z) [MIM:[http://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:[http://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> [[http://www.uniprot.org/uniprot/TNNI3_HUMAN TNNI3_HUMAN]] Defects in TNNI3 are the cause of familial hypertrophic cardiomyopathy type 7 (CMH7) [MIM:[http://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:[http://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:[http://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:[http://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 == | ||
| + | [[http://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. [[http://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. | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == Publication Abstract from PubMed == | ||
| + | Intracellular acidosis lowers the Ca2+ sensitivity of cardiac muscle, which results in decreased force generation, decreased cardiac output, and, eventually, heart failure. The A162H mutant of cardiac troponin I in the thin filament turns the heart acidosis-resistant. Physiological and structural studies have provided insights into the mechanism of protection by the A162H substitution; however, the effect of other native residues of cardiac troponin I is not fully understood. In this study, we determined the structure of the A162H mutant of the switch region of cardiac troponin I bound to the regulatory domain of troponin C at pH 6.1, and the dynamics as a function of pH, by NMR spectroscopy to evaluate the changes induced by protonation of A162H. The results indicate that A162H induces a transitory curved conformation on troponin I that promotes contraction, but it is countered by residue E164 to ensure proper relaxation. Our model explains the absence of diastolic impairment in the gain-of-function phenotype induced by the A162H substitution as well as the effects of a variety of mutants studied previously. The description of this mechanism underlines the fine quality of regulation on cardiac muscle contraction and anticipates pharmacological agents that induce modest changes in the contraction-relaxation equilibrium to produce marked effects in cardiac performance. | ||
| - | + | Structure and Dynamics of the Acidosis-Resistant A162H Mutant of the Switch Region of Troponin I Bound to the Regulatory Domain of Troponin C.,Pineda-Sanabria SE, Robertson IM, Sykes BD Biochemistry. 2015 Jun 2. PMID:25996354<ref>PMID:25996354</ref> | |
| - | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
| - | + | </div> | |
| - | + | == References == | |
| - | [[Category: | + | <references/> |
| - | [[Category: | + | __TOC__ |
| - | [[Category: | + | </StructureSection> |
| - | [[Category: | + | [[Category: Robertson, I M]] |
| + | [[Category: Sanabria, S E.Pineda]] | ||
| + | [[Category: Sykes, B D]] | ||
| + | [[Category: Acidosis]] | ||
| + | [[Category: Ca2+ binding]] | ||
| + | [[Category: Contractile protein]] | ||
| + | [[Category: Contraction enhancenment]] | ||
| + | [[Category: Contraction regulation]] | ||
| + | [[Category: Troponin]] | ||
Revision as of 12:37, 3 June 2015
Structure and dynamics of the acidosis-resistant a162H mutant of the switch region of troponin I bound to the regulatory domain of troponin C
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