3bx4

Crystal structure of the snake venom toxin aggretin

spinqualitylabelsall models 3bx4, resolution 1.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3bx4 is a 4 chain structure with sequence from Calloselasma rhodostoma. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: GOL, SO4 Resources: FirstGlance, OCA, RCSB, PDBsum 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 Aggretin is a C-type lectin purified from Calloselasma rhodostoma snake venom. It is a potent activator of platelets, resulting in a collagen-like response by binding and clustering platelet receptor CLEC-2. We present here the crystal structure of aggretin at 1.7 A which reveals a unique tetrameric quaternary structure. The two alphabeta heterodimers are arranged through 2-fold rotational symmetry, resulting in an antiparallel side-by-side arrangement. Aggretin thus presents two ligand binding sites on one surface and can therefore cluster ligands in a manner reminiscent of convulxin and flavocetin. To examine the molecular basis of the interaction with CLEC-2, we used a molecular modeling approach of docking the aggretin alphabeta structure with the CLEC-2 N-terminal domain (CLEC-2N). This model positions the CLEC-2N structure face down in the "saddle"-shaped binding site which lies between the aggretin alpha and beta lectin-like domains. A 2-fold rotation of this complex to generate the aggretin tetramer reveals dimer contacts for CLEC-2N which bring the N- and C-termini into the proximity of each other, and a series of contacts involving two interlocking beta-strands close to the N-terminus are described. A comparison with homologous lectin-like domains from the immunoreceptor family reveals a similar but not identical dimerization mode, suggesting this structure may represent the clustered form of CLEC-2 capable of signaling across the platelet membrane. The crystal structure of the platelet activator aggretin reveals a novel (alphabeta)2 dimeric structure.,Hooley E, Papagrigoriou E, Navdaev A, Pandey AV, Clemetson JM, Clemetson KJ, Emsley J Biochemistry. 2008 Jul 29;47(30):7831-7. Epub 2008 Jul 3. PMID:18597489 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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