1q5t

Gln48 PLA2 separated from Vipoxin from the venom of Vipera ammodytes meridionalis.

spinqualitylabelsall models 1q5t, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1q5t is a 2 chain structure with sequence from Vipera ammodytes meridionalis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: SO4 Resources: FirstGlance, OCA, RCSB, PDBsum Function [PA2I_VIPAE] Heterodimer: postsynaptic neurotoxin. Monomer: Acidic phospholipase A2 homolog that is non-toxic. 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 Phospholipase A2 is an "interfacial" enzyme and its binding to negatively charged surfaces is an important step during catalysis. The Gln48 phospholipase A2 from the venom of Vipera ammodytes meridionalis plays the role of chaperone and directs a toxic His48 PLA2 onto its acceptor. In the venom the two phospholipases A2 exist as a postsynaptic neurotoxic complex, Vipoxin. The X-ray structure of Gln48 PLA2, complexed to sulphate ions, which mimic the negatively charged groups of anionic membranes, has been determined by the molecular replacement method and refined to 1.9A resolution. The protein forms a homodimer stabilized by ionic, hydrophobic, and hydrogen-bond interactions. The structure reveals two anion-binding sites per subunit. These sites are probably involved in interactions with the negatively charged membrane surface and, in this way, in the "targeting" of the toxic component to the receptors of the postsynaptic membranes. In the absence of the chaperone subunit the toxin changes the target of the physiological attack. A comparison of the homodimeric Gln48 PLA2 structure with that of the heterodimeric Vipoxin reveals differences in regions involved in the pharmacological activity of the toxin. This fact, except the active site histidine substitution, can explain the absence of toxicity in the Gln48 protein in comparison to the His48 phospholipase A2. The X-ray structure of a snake venom Gln48 phospholipase A2 at 1.9A resolution reveals anion-binding sites.,Georgieva DN, Perbandt M, Rypniewski W, Hristov K, Genov N, Betzel C Biochem Biophys Res Commun. 2004 Mar 26;316(1):33-8. PMID:15003507 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Phospholipase A2

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