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1koz
From Proteopedia
(New page: 200px<br /><applet load="1koz" size="450" color="white" frame="true" align="right" spinBox="true" caption="1koz" /> '''SOLUTION STRUCTURE OF OMEGA-GRAMMOTOXIN SIA'...) |
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| - | [[Image:1koz.gif|left|200px]]<br /><applet load="1koz" size=" | + | [[Image:1koz.gif|left|200px]]<br /><applet load="1koz" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1koz" /> | caption="1koz" /> | ||
'''SOLUTION STRUCTURE OF OMEGA-GRAMMOTOXIN SIA'''<br /> | '''SOLUTION STRUCTURE OF OMEGA-GRAMMOTOXIN SIA'''<br /> | ||
==Overview== | ==Overview== | ||
| - | omega-Grammotoxin SIA (GrTx) is a 36 amino acid residue protein toxin from | + | omega-Grammotoxin SIA (GrTx) is a 36 amino acid residue protein toxin from spider venom that inhibits P/Q and N-type voltage-gated Ca(2+) channels by modifying voltage-dependent gating. We determined the three-dimensional structure of GrTx using NMR spectroscopy. The toxin adopts an "inhibitor cystine knot" motif composed of two beta-strands (Leu19-Cys21 and Cys30-Trp32) and a beta-bulge (Trp6, Gly7-Cys30) with a +2x, -1 topology, which are connected by four chain reversals. Although GrTx was originally identified as an inhibitor of voltage-gated Ca(2+) channel, it also binds to K(+) channels with lower affinity. A similar cross-reaction was observed for Hanatoxin1 (HaTx), which binds to the voltage-sensing domains of K(+) and Ca(2+) channels with different affinities. A detailed comparison of the GrTx and HaTx structures identifies a conserved face containing a large hydrophobic patch surrounded by positively charged residues. The slight differences in the surface shape, which result from the orientation of the surface aromatic residues and/or the distribution of the charged residues, may explain the differences in the binding affinity of these gating modifiers with different voltage-gated ion channels. |
==About this Structure== | ==About this Structure== | ||
| - | 1KOZ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http:// | + | 1KOZ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KOZ OCA]. |
==Reference== | ==Reference== | ||
Solution structure of omega-grammotoxin SIA, a gating modifier of P/Q and N-type Ca(2+) channel., Takeuchi K, Park E, Lee C, Kim J, Takahashi H, Swartz K, Shimada I, J Mol Biol. 2002 Aug 16;321(3):517-26. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=12162963 12162963] | Solution structure of omega-grammotoxin SIA, a gating modifier of P/Q and N-type Ca(2+) channel., Takeuchi K, Park E, Lee C, Kim J, Takahashi H, Swartz K, Shimada I, J Mol Biol. 2002 Aug 16;321(3):517-26. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=12162963 12162963] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Kim, J | + | [[Category: Kim, J I.]] |
| - | [[Category: Lee, C | + | [[Category: Lee, C W.]] |
| - | [[Category: Park, E | + | [[Category: Park, E J.]] |
[[Category: Shimada, I.]] | [[Category: Shimada, I.]] | ||
| - | [[Category: Swartz, K | + | [[Category: Swartz, K J.]] |
[[Category: Takahashi, H.]] | [[Category: Takahashi, H.]] | ||
[[Category: Takeuchi, K.]] | [[Category: Takeuchi, K.]] | ||
| Line 22: | Line 22: | ||
[[Category: toxin]] | [[Category: toxin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:36:24 2008'' |
Revision as of 11:36, 21 February 2008
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SOLUTION STRUCTURE OF OMEGA-GRAMMOTOXIN SIA
Overview
omega-Grammotoxin SIA (GrTx) is a 36 amino acid residue protein toxin from spider venom that inhibits P/Q and N-type voltage-gated Ca(2+) channels by modifying voltage-dependent gating. We determined the three-dimensional structure of GrTx using NMR spectroscopy. The toxin adopts an "inhibitor cystine knot" motif composed of two beta-strands (Leu19-Cys21 and Cys30-Trp32) and a beta-bulge (Trp6, Gly7-Cys30) with a +2x, -1 topology, which are connected by four chain reversals. Although GrTx was originally identified as an inhibitor of voltage-gated Ca(2+) channel, it also binds to K(+) channels with lower affinity. A similar cross-reaction was observed for Hanatoxin1 (HaTx), which binds to the voltage-sensing domains of K(+) and Ca(2+) channels with different affinities. A detailed comparison of the GrTx and HaTx structures identifies a conserved face containing a large hydrophobic patch surrounded by positively charged residues. The slight differences in the surface shape, which result from the orientation of the surface aromatic residues and/or the distribution of the charged residues, may explain the differences in the binding affinity of these gating modifiers with different voltage-gated ion channels.
About this Structure
1KOZ is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.
Reference
Solution structure of omega-grammotoxin SIA, a gating modifier of P/Q and N-type Ca(2+) channel., Takeuchi K, Park E, Lee C, Kim J, Takahashi H, Swartz K, Shimada I, J Mol Biol. 2002 Aug 16;321(3):517-26. PMID:12162963
Page seeded by OCA on Thu Feb 21 13:36:24 2008
