1qs3: Difference between revisions

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-{{STRUCTURE_1qs3|  PDB=1qs3  |  SCENE=  }}
+==NMR SOLUTION CONFORMATION OF AN ANTITOXIC ANALOG OF ALPHA-CONOTOXIN GI==
-===NMR SOLUTION CONFORMATION OF AN ANTITOXIC ANALOG OF ALPHA-CONOTOXIN GI===
+<StructureSection load='1qs3' size='340' side='right' caption='[[1qs3]], [[NMR_Ensembles_of_Models | 30 NMR models]]' scene=''>
-{{ABSTRACT_PUBMED_10508392}}
+== Structural highlights ==
+<table><tr><td colspan='2'>[[1qs3]] is a 1 chain structure. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QS3 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1QS3 FirstGlance]. <br>
+</td></tr><tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><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'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1qs3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1qs3 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1qs3 RCSB], [http://www.ebi.ac.uk/pdbsum/1qs3 PDBsum]</span></td></tr>
+</table>
+<div style="background-color:#fffaf0;">
+== Publication Abstract from PubMed ==
+The three-dimensional solution conformation of an 11-residue antitoxic analogue of alpha-conotoxin GI, des-Glu1-[Cys3Ala]-des-Cys13-conotoxin GI (CANPACGRHYS-NH(2), designated "GI-15" henceforth), has been determined using two-dimensional (1)H NMR spectroscopy. The disulfide loop region (1C-6C) and the C-terminal tail (8R-11S) are connected by a flexible hinge formed near 7G, and the pairwise backbone rmsds for the former and the latter are 0.58 and 0.65 A, respectively. Superpositioning GI-15 with the structure of alpha-conotoxin GI shows that the two share an essentially identical fold in the common first disulfide loop region (1C-6C). However, the absence of the second disulfide loop in GI-15 results in segmental motion of the C-terminal half, causing the key receptor subtype selectivity residue 8R (Arg9 in alpha-conotoxin GI) to lose its native spatial orientation. The combined features of structural equivalence in the disulfide loop and a mobile C-terminal tail appear to be responsible for the activity of GI-15 as a competitive antagonist against native toxin. Electrostatic surface potential comparisons of the first disulfide region of GI-15 with other alpha-conotoxins or receptor-bound states of acetylcholine and d-tubocurarine show a common protruding surface that may serve as the minimal binding determinant for the neuromuscular acetylcholine receptor alpha 1-subunit. On the basis of the original "Conus toxin macrosite model" [Olivera, B. M., Rivier, J., Scott, J. K., Hillyard, D. R., and Cruz, L. J. (1991) J. Biol. Chem. 266, 1923-1936], we propose a revised binding model which incorporates these results.
-==Function==
+NMR solution conformation of an antitoxic analogue of alpha-conotoxin GI: identification of a common nicotinic acetylcholine receptor alpha 1-subunit binding surface for small ligands and alpha-conotoxins.,Mok KH, Han KH Biochemistry. 1999 Sep 14;38(37):11895-904. PMID:10508392<ref>PMID:10508392</ref>
-[[http://www.uniprot.org/uniprot/CA1A_CONGE CA1A_CONGE]] Alpha-conotoxins act on postsynaptic membranes, they bind to the nicotinic acetylcholine receptors (nAChR) and thus inhibit them. The higher affinity site for alpha-conotoxin GI is the alpha/delta site on mouse muscle-derived BC3H-1 receptor, and the other site (alpha/gamma site) on nicotinic receptors from Torpedo californica electric organ.
-==About this Structure==
+From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
-[[1qs3]] is a 1 chain structure. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QS3 OCA].
+</div>
+== References ==
-==Reference==
+<references/>
-<ref group="xtra">PMID:010508392</ref><references group="xtra"/><references/>
+__TOC__
-[[Category: Han, K H.]]
+</StructureSection>
-[[Category: Mok, K H.]]
+[[Category: Han, K H]]
+[[Category: Mok, K H]]
 [[Category: Antitoxic analog]]
 [[Category: Conotoxin]]
 [[Category: Nicotinic acetylcholine receptor]]
 [[Category: Toxin]]