View source for 1vib


==NMR SOLUTION STRUCTURE OF THE NEUROTOXIN B-IV, 20 STRUCTURES==
<StructureSection load='1vib' size='340' side='right'caption='[[1vib]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1vib]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Cerebratulus_lacteus Cerebratulus lacteus]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1VIB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1VIB FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR, 20 models</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HYP:4-HYDROXYPROLINE'>HYP</scene></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=1vib FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1vib OCA], [https://pdbe.org/1vib PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1vib RCSB], [https://www.ebi.ac.uk/pdbsum/1vib PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1vib ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/NXB4_CERLA NXB4_CERLA] This toxin increases the excitability of nerves by delaying the inactivation of the voltage-gated sodium channel (Nav). Only acts on some crustacean. Neurotoxin B-IV is more abundant, but 15-fold less toxic than neurotoxin B-II.
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== Publication Abstract from PubMed ==
B-IV is a 55-residue, crustacean-selective, neurotoxin secreted by Cerebratulus lacteus, a large marine worm found along the northeastern coast of North America. The 3D structure of this molecule in aqueous solution has been determined by 1H NMR spectroscopy at 600 MHz. The molecule has a well-defined helical hairpin structure, with the branches of the hairpin linked by four disulphide bonds. The disulphide connectivities were established from the NMR data to be 1-8/2-7/3-6/4-5, which differed from those determined previously by chemical means, where 1-7 and 2-8 connectivities were found. Each branch of the hairpin is largely alpha-helical, with the helices in the N and C-terminal branches encompassing residues 11 to 23 and 34 to 49, respectively. The loop connecting the branches of the hairpin contains two inverse gamma-turns centred on residues 24 and 25, a type I beta-turn at residues 28 to 31 and a type II beta-turn at residues 30 to 33. Arg17, -25 and -34, which are important for activity, are all on the same face of the molecule, while Trp30, which is also important for activity, is on the opposite face. Structure comparisons show that the B-IV structure is quite similar to those of Rop (ColE1 repressor of primer) and the heat-stable enterotoxin B from Escherichia coli. These structural similarities are discussed in relation to possible mechanisms of action of B-IV.

Structure of neurotoxin B-IV from the marine worm Cerebratulus lacteus: a helical hairpin cross-linked by disulphide bonding.,Barnham KJ, Dyke TR, Kem WR, Norton RS J Mol Biol. 1997 May 23;268(5):886-902. PMID:9180379<ref>PMID:9180379</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 1vib" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Cerebratulus lacteus]]
[[Category: Large Structures]]
[[Category: Barnham KJ]]
[[Category: Dyke TR]]
[[Category: Kem WR]]
[[Category: Norton RS]]