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STRUCTURE AND INTERACTION SITE OF THE REGULATORY DOMAIN OF TROPONIN-C WHEN COMPLEXED WITH THE 96-148 REGION OF TROPONIN-I, NMR, 29 STRUCTURESSTRUCTURE AND INTERACTION SITE OF THE REGULATORY DOMAIN OF TROPONIN-C WHEN COMPLEXED WITH THE 96-148 REGION OF TROPONIN-I, NMR, 29 STRUCTURES
Structural highlights
FunctionTNNC2_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![]() Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe structure of the regulatory domain of chicken skeletal troponin-C (residues 1-90) when complexed with the major inhibitory region (residues 96-148) of chicken skeletal troponin-I was determined using multinuclear, multidimensional NMR spectroscopy. This complex represents the first interaction formed between the regulatory domain of troponin-C and troponin-I after calcium binding in the regulation of muscle contraction. The stoichiometry of the complex was determined to be 1:1, with a dissociation constant in the 1-40 microM range. The structure of troponin-C in the complex was calculated from 1039 NMR distance and 111 dihedral angle restraints. When compared to the structure of this domain in the calcium saturated "open" form but in the absence of troponin-I, the bound structure appears to be slightly more "closed". The troponin-I peptide-binding site was found to be in the hydrophobic pocket of calcium saturated troponin-C, using edited/filtered NMR experiments and chemical shift mapping of changes induced in the regulatory domain upon peptide binding. The troponin-I peptide (residues 96-148) was found to bind to the regulatory domain of troponin-C very similarly, but not identically, to a shorter troponin-I peptide (region 115-131) thought to represent the major interaction site of troponin-I for this domain of troponin-C. Structure and interaction site of the regulatory domain of troponin-C when complexed with the 96-148 region of troponin-I.,McKay RT, Pearlstone JR, Corson DC, Gagne SM, Smillie LB, Sykes BD Biochemistry. 1998 Sep 8;37(36):12419-30. PMID:9730814[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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