6d42
From Proteopedia
(Difference between revisions)
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| - | '''Unreleased structure''' | ||
| - | The entry | + | ==Crystal structure of the KCa3.1 C-terminal four-helix bundle (with copper)== |
| + | <StructureSection load='6d42' size='340' side='right' caption='[[6d42]], [[Resolution|resolution]] 1.75Å' scene=''> | ||
| + | == Structural highlights == | ||
| + | <table><tr><td colspan='2'>[[6d42]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6D42 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6D42 FirstGlance]. <br> | ||
| + | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CU:COPPER+(II)+ION'>CU</scene></td></tr> | ||
| + | <tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene></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=6d42 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6d42 OCA], [http://pdbe.org/6d42 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6d42 RCSB], [http://www.ebi.ac.uk/pdbsum/6d42 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6d42 ProSAT]</span></td></tr> | ||
| + | </table> | ||
| + | == Disease == | ||
| + | [[http://www.uniprot.org/uniprot/KCNN4_HUMAN KCNN4_HUMAN]] The disease is caused by mutations affecting the gene represented in this entry. | ||
| + | == Function == | ||
| + | [[http://www.uniprot.org/uniprot/KCNN4_HUMAN KCNN4_HUMAN]] Forms a voltage-independent potassium channel that is activated by intracellular calcium (PubMed:26148990). Activation is followed by membrane hyperpolarization which promotes calcium influx. Required for maximal calcium influx and proliferation during the reactivation of naive T-cells. The channel is blocked by clotrimazole and charybdotoxin but is insensitive to apamin (PubMed:17157250, PubMed:18796614).<ref>PMID:17157250</ref> <ref>PMID:18796614</ref> <ref>PMID:26148990</ref> | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == Publication Abstract from PubMed == | ||
| + | KCa3.1 (also known as SK4 or IK1) is a mammalian intermediate-conductance potassium channel that plays a critical role in the activation of T cells, B cells, and mast cells, effluxing potassium ions to maintain a negative membrane potential for influxing calcium ions. KCa3.1 shares primary sequence similarity with three other (low-conductance) potassium channels: KCa2.1, KCa2.2, and KCa2.3 (also known as SK1-3). These four homotetrameric channels bind calmodulin (CaM) in the cytoplasmic region, and calcium binding to CaM triggers channel activation. Unique to KCa3.1, activation also requires phosphorylation of a single histidine residue, His358, in the cytoplasmic region, which relieves copper-mediated inhibition of the channel. Near the cytoplasmic C-terminus of KCa3.1 (and KCa2.1-2.3), secondary-structure analysis predicts the presence of a coiled-coil/heptad repeat. Here, we report the crystal structure of the C-terminal coiled-coil region of KCa3.1, which forms a parallel four-helix bundle, consistent with the tetrameric nature of the channel. Interestingly, the four copies of a histidine residue, His389, in an 'a' position within the heptad repeat, are observed to bind a copper ion along the four-fold axis of the bundle. These results suggest that His358, the inhibitory histidine in KCa3.1, might coordinate a copper ion through a similar binding mode. | ||
| - | + | Crystal structure of the C-terminal four-helix bundle of the potassium channel KCa3.1.,Ji T, Corbalan-Garcia S, Hubbard SR PLoS One. 2018 Jun 28;13(6):e0199942. doi: 10.1371/journal.pone.0199942., eCollection 2018. PMID:29953543<ref>PMID:29953543</ref> | |
| - | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
| - | [[Category: | + | </div> |
| + | <div class="pdbe-citations 6d42" style="background-color:#fffaf0;"></div> | ||
| + | == References == | ||
| + | <references/> | ||
| + | __TOC__ | ||
| + | </StructureSection> | ||
| + | [[Category: Hubbard, S R]] | ||
[[Category: Ji, T]] | [[Category: Ji, T]] | ||
| - | [[Category: | + | [[Category: Copper]] |
| + | [[Category: Four-helix bundle]] | ||
| + | [[Category: Membrane protein]] | ||
Revision as of 05:42, 11 July 2018
Crystal structure of the KCa3.1 C-terminal four-helix bundle (with copper)
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