1ONJ
Crystal structure of Atratoxin-b from Chinese cobra venom of Naja atra
Summary for 1ONJ
| Entry DOI | 10.2210/pdb1onj/pdb |
| Descriptor | Cobrotoxin b, SULFATE ION (3 entities in total) |
| Functional Keywords | beta-turn-beta, three-finger protein, toxin |
| Biological source | Naja atra (Chinese cobra) |
| Cellular location | Secreted : P80958 |
| Total number of polymer chains | 1 |
| Total formula weight | 6939.75 |
| Authors | |
| Primary citation | Lou, X.,Tu, X.,Pan, G.,Xu, C.,Fan, R.,Lu, W.,Deng, W.,Rao, P.,Teng, M.,Niu, L. Purification, N-terminal sequencing, crystallization and preliminary structural determination of atratoxin-b, a short-chain alpha-neurotoxin from Naja atra venom. Acta Crystallogr.,Sect.D, 59:1038-1042, 2003 Cited by PubMed Abstract: 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). PubMed: 12777767DOI: 10.1107/S0907444903005687 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.555 Å) |
Structure validation
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