2ccx

DETERMINATION OF THE NUCLEAR MAGNETIC RESONANCE SOLUTION STRUCTURE OF CARDIOTOXIN CTX IIB FROM NAJA MOSSAMBICA MOSSAMBICA

spinqualitylabelsall models 2ccx Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2ccx is a 1 chain structure with sequence from Naja mossambica. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Solution NMR, 20 models Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function 3SA1_NAJMO Shows cytolytic activity on many different cells by forming pore in lipid membranes. In vivo, increases heart rate or kills the animal by cardiac arrest. In addition, it binds to heparin with high affinity, interacts with Kv channel-interacting protein 1 (KCNIP1) in a calcium-independent manner, and binds to integrin alpha-V/beta-3 (ITGAV/ITGB3) with moderate affinity.[UniProtKB:P60301][UniProtKB:P60304] 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 The NMR structure of cardiotoxin CTX IIb from Naja mossambica mossambica in aqueous solution was determined from a total of 593 nuclear Overhauser enhancement distance constraints and 135 dihedral angle constraints, which were collected using two-dimensional homonuclear 1H-NMR experiments. Structure calculations were performed with the program DIANA, using the redundant dihedral angle constraints strategy for improved convergence, followed by restrained energy minimization with the program FANTOM and a modified version of the program AMBER. The CTX IIb structure is represented by a group of 20 conformers with an average root-mean-square deviation relative to the mean solution structure of 0.072 nm for the backbone atoms, and 0.116 nm for all heavy atoms. The molecular structure of CTX IIb is characterized by a three-stranded beta-sheet made up of residues 20-26, 32-39 and 48-54, and a two-stranded beta-sheet composed of residues 1-5 and 10-14. A cluster of four disulfide bonds, 3-21, 14-38, 42-53 and 54-59, form the core of the molecule and crosslink the individual polypeptide strands. The NMR structure is similar to the previously reported X-ray crystal structure of the cardiotoxin CTX VII4 from the same species. Differences between the two structures were noted in the tips of the two loops formed by residues 6-9 and 27-31, which connect the beta-strand 1-5 with 10-14, and 20-26 with 32-39, respectively. For these loops the NMR data also indicate significantly increased dynamic disorder in the solution structure. These observations are discussed with respect to earlier suggestions by others that these two loops are essential structural elements for function and specificity of a wide variety of homologous toxins. Determination of the nuclear-magnetic-resonance solution structure of cardiotoxin CTX IIb from Naja mossambica mossambica.,O'Connell JF, Bougis PE, Wuthrich K Eur J Biochem. 1993 May 1;213(3):891-900. PMID:8504828 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Cardiotoxin 3D structures

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