1dtl

CRYSTAL STRUCTURE OF CALCIUM-SATURATED (3CA2+) CARDIAC TROPONIN C COMPLEXED WITH THE CALCIUM SENSITIZER BEPRIDIL AT 2.15 A RESOLUTION

spinqualitylabelsall models 1dtl, resolution 2.15Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1dtl is a 1 chain structure with sequence from Gallus gallus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.15Å Ligands: BEP, CA Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function 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 Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Cardiac troponin C (cTnC) is the calcium-dependent switch for contraction in heart muscle and a potential target for drugs in the therapy of congestive heart failure. This calmodulin-like protein consists of two lobes connected by a central linker; each lobe contains two EF-hand domains. The regulatory N-terminal lobe of cTnC, unlike that of skeletal troponin C (sTnC), contains only one functional EF-hand and does not open fully upon the binding of Ca(2+). We have determined the crystal structure of cTnC, with three bound Ca(2+) ions, complexed with the calcium-sensitizer bepridil, to 2.15-A resolution. In contrast to apo- and 3Ca(2+)-cTnC, the drug-bound complex displays a fully open N-terminal lobe similar to the N-terminal lobes of 4Ca(2+)-sTnC and cTnC bound to a C-terminal fragment of cardiac troponin I (residues 147-163). The closing of the lobe is sterically hindered by one of the three bound bepridils. Our results provide a structural basis for the Ca(2+)-sensitizing effect of bepridil and reveal the details of a distinctive two-stage mechanism for Ca(2+) regulation by troponin C in cardiac muscle. Bepridil opens the regulatory N-terminal lobe of cardiac troponin C.,Li Y, Love ML, Putkey JA, Cohen C Proc Natl Acad Sci U S A. 2000 May 9;97(10):5140-5. PMID:10792039 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Troponin 3D structures

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