View source for 1awy


==NMR STRUCTURE OF CALCIUM BOUND CONFORMER OF CONANTOKIN G, MINIMIZED AVERAGE STRUCTURE==
<StructureSection load='1awy' size='340' side='right'caption='[[1awy]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1awy]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Conus_geographus Conus geographus]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AWY OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1AWY FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CGU:GAMMA-CARBOXY-GLUTAMIC+ACID'>CGU</scene>, <scene name='pdbligand=NH2:AMINO+GROUP'>NH2</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=1awy FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1awy OCA], [https://pdbe.org/1awy PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1awy RCSB], [https://www.ebi.ac.uk/pdbsum/1awy PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1awy ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CKG_CONGE CKG_CONGE] Conantokins inhibit N-methyl-D-aspartate (NMDA) receptors. This toxin is selective for the NR2B/GRIN2B subunit. Induces sleep-like symptoms in young mice and hyperactivity in older mice.<ref>PMID:2165278</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Conantokin G is a gamma-carboxyglutamic acid- (Gla-) containing conotoxin isolated from the venom of the marine cone snail Conus geographus. This 17-residue polypeptide, which contains five gamma-carboxyglutamic acid residues, is a N-methyl-d-aspartate- (NMDA-) type glutamate receptor antagonist. To investigate the role of gamma-carboxyglutamic acid in the calcium-induced structural transition of conantokin G, we determined the three-dimensional structure of the conantokin G/Ca2+ complex by two-dimensional 1H NMR spectroscopy and compared it to the high-resolution structure of conantokin G in the absence of metal ions [Rigby et al. (1997) Biochemistry 36, 6906]. Complete resonance assignments were made by two dimensional 1H NMR spectroscopy at pH 5.6 in the presence of saturating amounts of Ca2+. Distance geometry and simulated annealing methods were used to derive 23 convergent structures from a set of 302 interproton distance restraints and two torsion angle measurements. A high-resolution structure, with the backbone root mean square deviation to the geometric average of the 23 structures of 0.6 +/- 0.1 A, contains a linear alpha-helix from Gla 3 to Lys 15. Gla residues 3, 7, 10, and 14 are aligned in a linear array on one face of the helix. A genetic algorithm was applied to determine the calcium positions in conantokin G, and the conantokin G/Ca2+ complex refined by molecular simulation. Upon binding of Ca2+ to gamma-carboxyglutamic acid, conantokin G undergoes a conformational transition from a distorted curvilinear 310 helix to a linear alpha-helix. Occupancy of the metal binding sites, defined by gamma-carboxyglutamic acids, results in formation of a calcium-carboxylate network that linearizes the helix and exposes the hydrophobic amino acids on the opposite face of the helix.

Role of gamma-carboxyglutamic acid in the calcium-induced structural transition of conantokin G, a conotoxin from the marine snail Conus geographus.,Rigby AC, Baleja JD, Li L, Pedersen LG, Furie BC, Furie B Biochemistry. 1997 Dec 16;36(50):15677-84. PMID:9398296<ref>PMID:9398296</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1awy" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Conus geographus]]
[[Category: Large Structures]]
[[Category: Baleja JD]]
[[Category: Furie B]]
[[Category: Furie BC]]
[[Category: Leping L]]
[[Category: Pedersen LG]]
[[Category: Rigby AC]]