1sn1: Difference between revisions

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-[[Image:1sn1.jpg|left|200px]]
-<!--
+==STRUCTURE OF SCORPION NEUROTOXIN BMK M1==
-The line below this paragraph, containing "STRUCTURE_1sn1", creates the "Structure Box" on the page.
+<StructureSection load='1sn1' size='340' side='right'caption='[[1sn1]], [[Resolution|resolution]] 1.70&Aring;' scene=''>
-You may change the PDB parameter (which sets the PDB file loaded into the applet)
+== Structural highlights ==
-or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
+<table><tr><td colspan='2'>[[1sn1]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Mesobuthus_martensii Mesobuthus martensii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SN1 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1SN1 FirstGlance]. <br>
-or leave the SCENE parameter empty for the default display.
+</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.7&#8491;</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=1sn1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1sn1 OCA], [https://pdbe.org/1sn1 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1sn1 RCSB], [https://www.ebi.ac.uk/pdbsum/1sn1 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1sn1 ProSAT]</span></td></tr>
-{{STRUCTURE_1sn1|  PDB=1sn1  |  SCENE=  }}
+</table>
+== Function ==
+[https://www.uniprot.org/uniprot/SCM1_MESMA SCM1_MESMA] Alpha toxins bind voltage-independently at site-3 of sodium channels (Nav) and inhibit the inactivation of the activated channels thereby blocking neuronal transmission. This toxin is active against both mammals and insects, and is classified as an alpha-like toxin. It is active on Nav1.2/SCN2A (EC(50)=139-252 nM), Nav1.3/SCN3A (EC(50)=565 nM), Nav1.4/SCN4A and Nav1.5/SCN5A (EC(50)=195-500 nM), Nav1.6/SCN8A (EC(50)=214 nM), and drosophila DmNav1 (EC(50)=30 nM) (PubMed:11322948, PubMed:12705833, PubMed:15677695, PubMed:19162162, PubMed:20678086). In mNav1.6/SCN8A, the toxin induces a large increase in both transient and persistent currents, which correlates with a prominent reduction in the fast component of inactivating current (PubMed:20678086). In rNav1.2/SCN2A and rNav1.3/SCN3A, toxin-increased currents is much smaller (PubMed:19162162, PubMed:20678086). Moreover, the toxin only accelerates the slow inactivation development and delay recovery of mNav1.6/SCN8A through binding to the channel in the open state (PubMed:20678086). Is 6-fold more toxic than BmK-M2. In vivo, intrahippocampal injection into rat induces epileptiform responses (PubMed:16229835). In addition, intraplantar injection into rat induces spontaneous nociception and hyperalgesia (PubMed:14554105).<ref>PMID:11322948</ref> <ref>PMID:12705833</ref> <ref>PMID:14554105</ref> <ref>PMID:15677695</ref> <ref>PMID:16229835</ref> <ref>PMID:19162162</ref> <ref>PMID:20678086</ref>
+== Evolutionary Conservation ==
+[[Image:Consurf_key_small.gif|200px|right]]
+Check<jmol>
+  <jmolCheckbox>
+    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/sn/1sn1_consurf.spt"</scriptWhenChecked>
+    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
+    <text>to colour the structure by Evolutionary Conservation</text>
+  </jmolCheckbox>
+</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1sn1 ConSurf].
+<div style="clear:both"></div>
-'''STRUCTURE OF SCORPION NEUROTOXIN BMK M1'''
+==See Also==
+*[[Potassium channel toxin 3D structures|Potassium channel toxin 3D structures]]
+== References ==
-==Overview==
+<references/>
-The crystal structures of two group III alpha-like toxins from the scorpion Buthus martensii Karsch, BmK M1 and BmK M4, were determined at 1.7 A and 1.3 A resolution and refined to R factors of 0.169 and 0.166, respectively. The first high-resolution structures of the alpha-like scorpion toxin show some striking features compared with structures of the "classical" alpha-toxin. Firstly, a non-proline cis peptide bond between residues 9 and 10 unusually occurs in the five-member reverse turn 8-12. Secondly, the cis peptide 9-10 mediates the spatial relationship between the turn 8-12 and the C-terminal stretch 58-64 through a pair of main-chain hydrogen bonds between residues 10 and 64 to form a unique tertiary arrangement which features the special orientation of the terminal residues 62-64. Finally, in consequence of the peculiar orientation of the C-terminal residues, the functional groups of Arg58, which are crucial for the toxin-receptor interaction, are exposed and accessible in BmK M1 and M4 rather than buried as in the classical alpha-toxins. Sequence alignment and characteristics analysis suggested that the above structural features observed in BmK M1 and M4 occur in all group III alpha-like toxins. Recently, some group III alpha-like toxins were demonstrated to occupy a receptor site different from the classical alpha-toxin. Therefore, the distinct structural features of BmK M1 and M4 presented here may provide the structural basis for the newly recognized toxin-receptor binding site selectivity. Besides, the non-proline cis peptide bonds found in these two structures play a role in the formation of the structural characteristics and in keeping accurate positions of the functionally crucial residues. This manifested a way to achieve high levels of molecular specificity and atomic precision through the strained backbone geometry.
+__TOC__
+</StructureSection>
-==About this Structure==
+[[Category: Large Structures]]
-SN1 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Mesobuthus_martensii Mesobuthus martensii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SN1 OCA].
-==Reference==
-Crystal structures of two alpha-like scorpion toxins: non-proline cis peptide bonds and implications for new binding site selectivity on the sodium channel., He XL, Li HM, Zeng ZH, Liu XQ, Wang M, Wang DC, J Mol Biol. 1999 Sep 10;292(1):125-35. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/10493862 10493862]
 [[Category: Mesobuthus martensii]]
-[[Category: Single protein]]
+[[Category: He XL]]
-[[Category: He, X L.]]
+[[Category: Li HM]]
-[[Category: Li, H M.]]
+[[Category: Liu XQ]]
-[[Category: Liu, X Q.]]
+[[Category: Wang DC]]
-[[Category: Wang, D C.]]
+[[Category: Zeng ZH]]
-[[Category: Zeng, Z H.]]
-[[Category: Neurotoxin]]
-[[Category: Scorpion]]
-[[Category: Sodium channel inhibitor]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 08:54:33 2008''