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1koz
From Proteopedia
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[[Image:1koz.gif|left|200px]] | [[Image:1koz.gif|left|200px]] | ||
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'''SOLUTION STRUCTURE OF OMEGA-GRAMMOTOXIN SIA''' | '''SOLUTION STRUCTURE OF OMEGA-GRAMMOTOXIN SIA''' | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1KOZ is a [[Single protein]] structure | + | 1KOZ is a [[Single protein]] structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KOZ OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Takahashi, H.]] | [[Category: Takahashi, H.]] | ||
[[Category: Takeuchi, K.]] | [[Category: Takeuchi, K.]] | ||
| - | [[Category: | + | [[Category: Cystine knot]] |
| - | [[Category: | + | [[Category: Toxin]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 22:59:58 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 19:59, 2 May 2008
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. 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 Fri May 2 22:59:58 2008
