3rv5

Crystal structure of human cardiac troponin C regulatory domain in complex with cadmium and deoxycholic acidCrystal structure of human cardiac troponin C regulatory domain in complex with cadmium and deoxycholic acid

Structural highlights 3rv5 is a 4 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: , , NonStd Res: Related: 1j1d, 1wrk, 1ap4, 1spy, 1mxl, 1lxf Gene: TNNC, TNNC1, TNNC1 (Amino acids 1-89) (Homo sapiens) Resources: FirstGlance, OCA, RCSB, PDBsum Disease [TNNC1_HUMAN] Defects in TNNC1 are the cause of cardiomyopathy dilated type 1Z (CMD1Z) [MIM: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. Defects in TNNC1 are the cause of familial hypertrophic cardiomyopathy type 13 (CMH13) [MIM: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. Function [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. Publication Abstract from PubMed The amino-terminal regulatory domain of cardiac troponin C (cNTnC) plays an important role as the calcium sensor for the troponin complex. Calcium binding to cNTnC results in conformational changes that trigger a cascade of events that lead to cardiac muscle contraction. The cardiac N-terminal domain of TnC consists of two EF-hand calcium binding motifs, one of which is dysfunctional in binding calcium. Nevertheless, the defunct EF-hand still maintains a role in cNTnC function. For its structural analysis by X-ray crystallography, human cNTnC with the wild-type primary sequence was crystallized under a novel crystallization condition. The crystal structure was solved by the single-wavelength anomalous dispersion method and refined to 2.2 A resolution. The structure displays several novel features. Firstly, both EF-hand motifs coordinate cadmium ions derived from the crystallization milieu. Secondly, the ion coordination in the defunct EF-hand motif accompanies unusual changes in the protein conformation. Thirdly, deoxycholic acid, also derived from the crystallization milieu, is bound in the central hydrophobic cavity. This is reminiscent of the interactions observed for cardiac calcium sensitizer drugs that bind to the same core region and maintain the "open" conformational state of calcium-bound cNTnC. The cadmium ion coordination in the defunct EF-hand indicates that this vestigial calcium binding site retains the structural and functional elements that allow it to coordinate a cadmium ion. However, it is a result of, or concomitant with, large and unusual structural changes in cNTnC. Crystal structure of cardiac troponin C regulatory domain in complex with cadmium and deoxycholic Acid reveals novel conformation.,Li AY, Lee J, Borek D, Otwinowski Z, Tibbits GF, Paetzel M J Mol Biol. 2011 Oct 28;413(3):699-711. Epub 2011 Sep 6. PMID:21920370 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Troponin

spinqualitylabelsall models 3rv5, resolution 2.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image