View source for 1s8i


==Crystal structure of Lys49-Phospholipase A2 from Agkistrodon contortrix laticinctus, second fatty acid free form==
<StructureSection load='1s8i' size='340' side='right'caption='[[1s8i]], [[Resolution|resolution]] 1.61&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1s8i]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Agkistrodon_laticinctus Agkistrodon laticinctus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1S8I OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1S8I 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]] 1.609&#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=1s8i FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1s8i OCA], [https://pdbe.org/1s8i PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1s8i RCSB], [https://www.ebi.ac.uk/pdbsum/1s8i PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1s8i ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PA2H1_AGKCL PA2H1_AGKCL] Snake venom phospholipase A2 homolog that has myotoxic activities. Lacks enzymatic activity.
== 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/s8/1s8i_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=1s8i ConSurf].
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== Publication Abstract from PubMed ==
Agkistrodon contortrix laticinctus myotoxin is a Lys(49)-phospholipase A(2) (EC 3.1.1.4) isolated from the venom of the serpent A. contortrix laticinctus (broad-banded copperhead). We present here three monomeric crystal structures of the myotoxin, obtained under different crystallization conditions. The three forms present notable structural differences and reveal that the presence of a ligand in the active site (naturally presumed to be a fatty acid) induces the exposure of a hydrophobic surface (the hydrophobic knuckle) toward the C terminus. The knuckle in A. contortrix laticinctus myotoxin involves the side chains of Phe(121) and Phe(124) and is a consequence of the formation of a canonical structure for the main chain within the region of residues 118-125. Comparison with other Lys(49)-phospholipase A(2) myotoxins shows that although the knuckle is a generic structural motif common to all members of the family, it is not readily recognizable by simple sequence analyses. An activation mechanism is proposed that relates fatty acid retention at the active site to conformational changes within the C-terminal region, a part of the molecule that has long been associated with Ca(2+)-independent membrane damaging activity and myotoxicity. This provides, for the first time, a direct structural connection between the phospholipase "active site" and the C-terminal "myotoxic site," justifying the otherwise enigmatic conservation of the residues of the former in supposedly catalytically inactive molecules.

A molecular mechanism for Lys49-phospholipase A2 activity based on ligand-induced conformational change.,Ambrosio AL, Nonato MC, de Araujo HS, Arni R, Ward RJ, Ownby CL, de Souza DH, Garratt RC J Biol Chem. 2005 Feb 25;280(8):7326-35. Epub 2004 Dec 13. PMID:15596433<ref>PMID:15596433</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1s8i" style="background-color:#fffaf0;"></div>

==See Also==
*[[Phospholipase A2 3D structures|Phospholipase A2 3D structures]]
*[[Phospholipase A2 homolog|Phospholipase A2 homolog]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Agkistrodon laticinctus]]
[[Category: Large Structures]]
[[Category: Ambrosio ALB]]
[[Category: Garratt RC]]
[[Category: Nonato MC]]
[[Category: Ownby CL]]
[[Category: Selistre de Araujo HS]]
[[Category: De Souza DHF]]