1axh

<StructureSection load='1axh' size='340' side='right'caption='[[1axh]], [[NMR_Ensembles_of_Models | 20 NMR models]]' scene=''>

<table><tr><td colspan='2'>[[1axh]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Atrax_versutus Atrax versutus]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AXH OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1AXH FirstGlance]. <br>

</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=1axh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1axh OCA], [http://pdbe.org/1axh PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1axh RCSB], [http://www.ebi.ac.uk/pdbsum/1axh PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1axh ProSAT]</span></td></tr>

== Function ==

[[http://www.uniprot.org/uniprot/TOT1A_HADVE TOT1A_HADVE]] Reversibly and voltage-independently blocks both mid-low- (M-LVA) and high-voltage-activated (HVA) calcium channels in cockroach DUM neurons. Lethal to many insect orders but not toxic to mice or rabbits. May target the insect high-voltage-activated calcium channel Dmca1D. Also inhibits acarines calcium channels. An extremely high toxin concentration partially inhibits Cav1.2/CACNA1C, Cav2.1/CACNA1A and Cav2.2/CACNA1B calcium channel of rats. As for omega-AcTx-Hv2a, the phenotypic effect of injection of this toxin into lone star ticks (Amblyomma americanum) is curling of all eight legs into closed loops.<ref>PMID:14608494</ref> <ref>PMID:15308644</ref> <ref>PMID:16330063</ref> <ref>PMID:17610847</ref> <ref>PMID:17141372</ref>

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== Publication Abstract from PubMed ==

A family of potent insecticidal toxins has recently been isolated from the venom of Australian funnel web spiders. Among these is the 37-residue peptide omega-atracotoxin-HV1 (omega-ACTX-HV1) from Hadronyche versuta. We have chemically synthesized and folded omega-ACTX-HV1, shown that it is neurotoxic, ascertained its disulphide bonding pattern, and determined its three-dimensional solution structure using NMR spectroscopy. The structure consists of a solvent-accessible beta-hairpin protruding from a disulphide-bonded globular core comprising four beta-turns. The three intramolecular disulphide bonds from a cystine knot motif similar to that seen in several other neurotoxic peptides. Despite limited sequence identity, omega-ACTX-HV1 displays significant structural homology with the omega-agatoxins and omega-conotoxins, both of which are vertebrate calcium channel antagonists; however, in contrast with these toxins, we show that omega-ACTX-HV1 inhibits insect, but not mammalian, voltage-gated calcium channel currents.

The structure of a novel insecticidal neurotoxin, omega-atracotoxin-HV1, from the venom of an Australian funnel web spider.,Fletcher JI, Smith R, O'Donoghue SI, Nilges M, Connor M, Howden ME, Christie MJ, King GF Nat Struct Biol. 1997 Jul;4(7):559-66. PMID:9228949<ref>PMID:9228949</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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<div class="pdbe-citations 1axh" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Atrax versutus]]

[[Category: Fletcher, J I]]

[[Category: King, G F]]

[[Category: Nilges, M]]

[[Category: Cystine knot]]

[[Category: Neurotoxin]]