View source for 1xta


==Crystal Structure of Natrin, a snake venom CRISP from Taiwan cobra (Naja atra)==
<StructureSection load='1xta' size='340' side='right'caption='[[1xta]], [[Resolution|resolution]] 1.58&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1xta]] is a 2 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=1XTA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1XTA 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]] 1.58&#8491;</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=1xta FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1xta OCA], [https://pdbe.org/1xta PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1xta RCSB], [https://www.ebi.ac.uk/pdbsum/1xta PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1xta ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CRVP1_NAJAT CRVP1_NAJAT] Inhibits calcium-activated potassium channels (KCa1.1/KCNMA1), voltage-gated potassium channel Kv1.3/KCNA3, and the calcium release channel/ryanodine receptor (RyR). Binds specifically to type 1 RyR (RyR1) from skeletal muscle. Inhibit both the binding of ryanodine to RyR1, and RyR1's calcium-channel activity. Inhibits carbachol-induced muscle contraction and weakly blocks muscle contraction evoked by potassium.<ref>PMID:15581679</ref> <ref>PMID:17070778</ref> <ref>PMID:18658224</ref> <ref>PMID:16042391</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/xt/1xta_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=1xta ConSurf].
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== Publication Abstract from PubMed ==
Cysteine-rich secretory proteins (CRISPs) play an important role in the innate immune system and are transcriptionally regulated by androgens in several tissues. The proteins are mostly found in the epididymis and granules of mammals, whilst a number of snake venoms also contain CRISP-family proteins. The natrin protein from the venom of Naja atra (Taiwan cobra), which belongs to a family of CRISPs and has a cysteine-rich C-terminal amino-acid sequence, has been purified using a three-stage chromatography procedure and crystals suitable for X-ray analysis have been obtained using the hanging-drop vapour-diffusion method. X-ray diffraction data were collected to 1.58 A resolution using synchrotron radiation; the crystals belong to space group C222(1), with unit-cell parameters a = 59.172, b = 65.038, c = 243.156 A. There are two protein molecules in the asymmetric unit and the Matthews coefficient is estimated to be 2.35 A3 Da(-1), corresponding to a solvent content of 47.60%.

Purification, crystallization and preliminary X-ray crystallographic analysis of a cysteine-rich secretory protein (CRISP) from Naja atra venom.,Wang YL, Goh KX, Wu WG, Chen CJ Acta Crystallogr D Biol Crystallogr. 2004 Oct;60(Pt 10):1912-5. Epub 2004, Sep 23. PMID:015388950<ref>PMID:015388950</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: Chen C-J]]
[[Category: Goh K-X]]
[[Category: Huang W-N]]
[[Category: Lee S-C]]
[[Category: Wang Y-L]]
[[Category: Wu W-G]]