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2ndi
From Proteopedia
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| - | '''Unreleased structure''' | ||
| - | + | ==Solution structure of the toxin ISTX-I from Ixodes scapularis== | |
| + | <StructureSection load='2ndi' size='340' side='right'caption='[[2ndi]]' scene=''> | ||
| + | == Structural highlights == | ||
| + | <table><tr><td colspan='2'>[[2ndi]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Ixodes_scapularis Ixodes scapularis]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2NDI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2NDI FirstGlance]. <br> | ||
| + | </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=2ndi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ndi OCA], [https://pdbe.org/2ndi PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2ndi RCSB], [https://www.ebi.ac.uk/pdbsum/2ndi PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2ndi ProSAT]</span></td></tr> | ||
| + | </table> | ||
| + | == Function == | ||
| + | [https://www.uniprot.org/uniprot/ISTX_IXOSC ISTX_IXOSC] By inhibiting Nav1.7/SCN9A sodium channel, may prevent signal transmission caused by tick penetration and the blood taken, allowing the tick to avoid discovery (PubMed:27407029). Weakly and specifically inhibits Nav1.7/SCN9A (IC(50)=1.6 uM) (PubMed:27407029). Significantly shifts the steady-state inactivation curve of the Nav1.7/SCN9A in the hyperpolarized direction (PubMed:27407029). Does not induce changes to I-V curve and conductance-voltage relationship (PubMed:27407029).<ref>PMID:27407029</ref> | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == Publication Abstract from PubMed == | ||
| + | Members of arachnida, such as spiders and scorpions, commonly produce venom with specialized venom glands, paralyzing their prey with neurotoxins that specifically target ion channels. Two well-studied motifs, the disulfide-directed hairpin (DDH) and the inhibitor cystine knot motif (ICK), are both found in scorpion and spider toxins. As arachnids, ticks inject a neurotoxin-containing cocktail from their salivary glands into the host to acquire a blood meal, but peptide toxins acting on ion channels have not been observed in ticks. Here, a new neurotoxin (ISTX-I) that acts on sodium channels was identified from the hard tick Ixodes scapularis and characterized. ISTX-I exhibits a potent inhibitory function with an IC50 of 1.6 muM for sodium channel Nav1.7 but not other sodium channel subtypes. ISTX-I adopts a novel structural fold and is distinct from the canonical ICK motif. Analysis of the ISTX-I, DDH and ICK motifs reveals that the new ISTX-I motif might be an intermediate scaffold between DDH and ICK, and ISTX-I is a clue to the evolutionary link between the DDH and ICK motifs. These results provide a glimpse into the convergent evolution of neurotoxins from predatory and blood-sucking arthropods. | ||
| - | + | A sodium channel inhibitor ISTX-I with a novel structure provides a new hint at the evolutionary link between two toxin folds.,Rong M, Liu J, Zhang M, Wang G, Zhao G, Wang G, Zhang Y, Hu K, Lai R Sci Rep. 2016 Jul 13;6:29691. doi: 10.1038/srep29691. PMID:27407029<ref>PMID:27407029</ref> | |
| - | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
| - | [[Category: | + | </div> |
| - | [[Category: Hu | + | <div class="pdbe-citations 2ndi" style="background-color:#fffaf0;"></div> |
| + | == References == | ||
| + | <references/> | ||
| + | __TOC__ | ||
| + | </StructureSection> | ||
| + | [[Category: Ixodes scapularis]] | ||
| + | [[Category: Large Structures]] | ||
| + | [[Category: Hu K]] | ||
Current revision
Solution structure of the toxin ISTX-I from Ixodes scapularis
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