View source for 1onj


==Crystal structure of Atratoxin-b from Chinese cobra venom of Naja atra==
<StructureSection load='1onj' size='340' side='right'caption='[[1onj]], [[Resolution|resolution]] 1.55&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1onj]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Naja_atra Naja atra]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ONJ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1ONJ FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.555&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1onj FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1onj OCA], [https://pdbe.org/1onj PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1onj RCSB], [https://www.ebi.ac.uk/pdbsum/1onj PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1onj ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/3S1CC_NAJAT 3S1CC_NAJAT] Binds to muscle nicotinic acetylcholine receptor (nAChR) and inhibit acetylcholine from binding to the receptor, thereby impairing neuromuscular transmission. Produces peripheral paralysis by blocking neuromuscular transmission at the postsynaptic site. Has a lower toxicity than cobrotoxin.<ref>PMID:9498573</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/on/1onj_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1onj ConSurf].
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== Publication Abstract from PubMed ==
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 (&gt;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).

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<ref>PMID:12777767</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Naja atra]]
[[Category: Deng W]]
[[Category: Fan R]]
[[Category: Lou X]]
[[Category: Lu W]]
[[Category: Niu L]]
[[Category: Pan G]]
[[Category: Rao P]]
[[Category: Teng M]]
[[Category: Tu X]]
[[Category: Xu C]]