1lir: Difference between revisions
From Proteopedia
Jump to navigationJump to search
No edit summary |
No edit summary |
||
| (13 intermediate revisions by the same user not shown) | |||
| Line 1: | Line 1: | ||
== | ==LQ2 FROM LEIURUS QUINQUESTRIATUS, NMR, 22 STRUCTURES== | ||
<StructureSection load='1lir' size='340' side='right'caption='[[1lir]]' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1lir]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Leiurus_quinquestriatus_hebraeus Leiurus quinquestriatus hebraeus]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LIR OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1LIR FirstGlance]. <br> | |||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PCA:PYROGLUTAMIC+ACID'>PCA</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=1lir FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1lir OCA], [https://pdbe.org/1lir PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1lir RCSB], [https://www.ebi.ac.uk/pdbsum/1lir PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1lir ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/KAX12_LEIHE KAX12_LEIHE] Blocks calcium-activated potassium channels (Kd=43 nM on KCa1.1/KCNMA1). Has a potent presynaptic facilitatory action, with less effect on direct muscle stimulation.<ref>PMID:2477548</ref> <ref>PMID:7533951</ref> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Lq2 is a unique scorpion toxin. Acting from the extracellular side, Lq2 blocks the ion conduction pore in not only the voltage- and Ca2+ -activated channels, but also the inward-rectifier K+ channels. This finding argues that the three-dimensional structures of the pores in these K+ channels are similar. However, the amino acid sequences that form the external part of the pore are minimally conserved among the various classes of K+ channels. Because Lq2 can bind to all the three classes of K+ channels, we can use Lq2 as a structural probe to examine how the non-conserved pore-forming sequences are arranged in space to form similar pore structures. In the present study, we determined the three-dimensional structure of Lq2 using nuclear magnetic resonance (NMR) techniques. Lq2 consists of an alpha-helix (residues S10 to L20) and a beta-sheet, connected by an alphabeta3 loop (residues N22 to N24). The beta-sheet has two well-defined anti-parallel strands (residues G26 to M29 and residues K32 to C35), which are connected by a type I' beta-turn centered between residues N30 and K31. The N-terminal segment (residues Z1 to T8) appears to form a quasi-third strand of the beta-sheet. | Lq2 is a unique scorpion toxin. Acting from the extracellular side, Lq2 blocks the ion conduction pore in not only the voltage- and Ca2+ -activated channels, but also the inward-rectifier K+ channels. This finding argues that the three-dimensional structures of the pores in these K+ channels are similar. However, the amino acid sequences that form the external part of the pore are minimally conserved among the various classes of K+ channels. Because Lq2 can bind to all the three classes of K+ channels, we can use Lq2 as a structural probe to examine how the non-conserved pore-forming sequences are arranged in space to form similar pore structures. In the present study, we determined the three-dimensional structure of Lq2 using nuclear magnetic resonance (NMR) techniques. Lq2 consists of an alpha-helix (residues S10 to L20) and a beta-sheet, connected by an alphabeta3 loop (residues N22 to N24). The beta-sheet has two well-defined anti-parallel strands (residues G26 to M29 and residues K32 to C35), which are connected by a type I' beta-turn centered between residues N30 and K31. The N-terminal segment (residues Z1 to T8) appears to form a quasi-third strand of the beta-sheet. | ||
Solution structure of potassium channel-inhibiting scorpion toxin Lq2.,Renisio JG, Lu Z, Blanc E, Jin W, Lewis JH, Bornet O, Darbon H Proteins. 1999 Mar 1;34(4):417-26. PMID:10081954<ref>PMID:10081954</ref> | |||
== | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
</div> | |||
<div class="pdbe-citations 1lir" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Potassium channel toxin 3D structures|Potassium channel toxin 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Leiurus quinquestriatus hebraeus]] | [[Category: Leiurus quinquestriatus hebraeus]] | ||
[[Category: Blanc E]] | |||
[[Category: Blanc | [[Category: Bornet O]] | ||
[[Category: Bornet | [[Category: Darbon H]] | ||
[[Category: Darbon | [[Category: Jin W]] | ||
[[Category: Jin | [[Category: Lewis JH]] | ||
[[Category: Lewis | [[Category: Lu Z]] | ||
[[Category: Lu | [[Category: Renisio JG]] | ||
[[Category: Renisio | |||
Latest revision as of 06:02, 5 July 2023
LQ2 FROM LEIURUS QUINQUESTRIATUS, NMR, 22 STRUCTURES
| ||||||||||||
