1g2x
From Proteopedia
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Sequence induced trimerization of krait PLA2: crystal structure of the trimeric form of krait PLA2
Overview
The venom of the common Indian krait (Bungarus caeruleus) contains about a, dozen isoforms of phospholipase A2 (PLA2), which exist in different, oligomeric forms as well as in complexes with low-molecular-weight, ligands. The basic objective of multimerization and complexation is either, to inactivate PLA2 in the venom for long-term storage, to generate a new, PLA2 function or to make a more lethal assembly. The current isoform was, isolated from the venom of B. caeruleus. Dynamic light-scattering studies, indicated the presence of a stable trimeric association of this PLA2. Its, primary sequence was determined by cDNA cloning. The purified protein was, crystallized with 2.8 M NaCl as a precipitating agent using the, sitting-drop vapour-diffusion method. The crystals belonged to the, monoclinic space group C2, with unit-cell parameters a = 80.9, b = 80.5, c, = 57.1 A, beta = 90.3 degrees. The structure was refined to a final R, factor of 0.198. This is a novel trimeric PLA2 structure in which the, central pore formed by the association of three molecules is filled with, water molecules. The interactions across the pore take place via multiple, water bridges primarily to the side chains of Arg, Lys and Thr residues., Approximately 12% of the total solvent-accessible surface area is buried, in the core of the trimer. The active sites of all three molecules are, located on the surface and are fully exposed to the solvent, resulting in, a highly potent enzymatic unit.
About this Structure
1G2X is a Single protein structure of sequence from Bungarus caeruleus. Active as Phospholipase A(2), with EC number 3.1.1.4 Full crystallographic information is available from OCA.
Reference
Sequence-induced trimerization of phospholipase A2: structure of a trimeric isoform of PLA2 from common krait (Bungarus caeruleus) at 2.5 A resolution., Singh G, Gourinath S, Saravanan K, Sharma S, Bhanumathi S, Betzel Ch, Srinivasan A, Singh TP, Acta Crystallograph Sect F Struct Biol Cryst Commun. 2005 Jan 1;61(Pt, 1):8-13. Epub 2004 Oct 16. PMID:16508078
Page seeded by OCA on Tue Nov 20 15:39:23 2007
