1onj

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Revision as of 20:55, 20 November 2007

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spinqualitylabelsall models 1onj, resolution 1.555Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal structure of Atratoxin-b from Chinese cobra venom of Naja atra

Overview

Atratoxin-b, a short-chain alpha-neurotoxin purified from Naja atra, (mainland Chinese cobra) venom using a three-step chromatography, procedure, has an apparent molecular mass of 6950 Da with an alkaline pI, value (>9.5) and consists of one single polypeptide chain as estimated by, MALDI-TOF mass spectrometry and SDS-PAGE. The protein is toxic to mice, with an in vitro LD(50) of about 0.18 mg kg(-1). Its N-terminal amino-acid, sequence, LECHNQQSSQTPTIT, displays a very high homology to those of other, alpha-neurotoxins. The overall three-dimensional structure of atratoxin-b, is very similar to that of the homologous erabutoxin-a, as shown by the, crystallographic molecular replacement and preliminary refinement results, with an R factor and R(free) of 27 and 29%, respectively. The microcrystal, slowly grew to dimensions of approximate 0.1 x 0.1 x 0.15 mm over eight, months using hanging-drop vapour-diffusion method. It gave a set of, diffraction data to 1.56 A resolution using X-rays of wavelength 1.1516 A, generated by the X-ray Diffraction and Scattering Station of beamline U7B, at the National Synchrotron Radiation Laboratory (Hefei, China); this is, the first example of the use of this beamline in protein crystallography., The crystals belong to the tetragonal space group P4(1)2(1)2, with, unit-cell parameters a = 49.28, c = 44.80 A, corresponding to one molecule, per asymmetric unit and a volume-to-mass ratio of 1.96 A(3) Da(-1).

About this Structure

1ONJ is a Single protein structure of sequence from Naja atra with SO4 as ligand. Full crystallographic information is available from OCA.

Reference

Purification, N-terminal sequencing, crystallization and preliminary structural determination of atratoxin-b, a short-chain alpha-neurotoxin from Naja atra venom., Lou X, Tu X, Pan G, Xu C, Fan R, Lu W, Deng W, Rao P, Teng M, Niu L, Acta Crystallogr D Biol Crystallogr. 2003 Jun;59(Pt 6):1038-42. Epub 2003, May 23. PMID:12777767

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