6ebm: Difference between revisions

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<SX load='6ebm' size='340' side='right' viewer='molstar' caption='[[6ebm]], [[Resolution|resolution]] 4.00&Aring;' scene=''>
<SX load='6ebm' size='340' side='right' viewer='molstar' caption='[[6ebm]], [[Resolution|resolution]] 4.00&Aring;' scene=''>
== Structural highlights ==
== Structural highlights ==
<table><tr><td colspan='2'>[[6ebm]] is a 4 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6EBM OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6EBM FirstGlance]. <br>
<table><tr><td colspan='2'>[[6ebm]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6EBM OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6EBM 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=6ebm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6ebm OCA], [http://pdbe.org/6ebm PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6ebm RCSB], [http://www.ebi.ac.uk/pdbsum/6ebm PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6ebm ProSAT]</span></td></tr>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 4&#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=6ebm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6ebm OCA], [https://pdbe.org/6ebm PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6ebm RCSB], [https://www.ebi.ac.uk/pdbsum/6ebm PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6ebm ProSAT]</span></td></tr>
</table>
</table>
== Function ==
== Function ==
[[http://www.uniprot.org/uniprot/KCNA2_RAT KCNA2_RAT]] Mediates the voltage-dependent potassium ion permeability of excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient.<ref>PMID:7544443</ref>
[https://www.uniprot.org/uniprot/KCNB2_RAT KCNB2_RAT] Voltage-gated potassium channel that mediates transmembrane potassium transport in excitable membranes, primarily in the brain and smooth muscle cells (PubMed:1550672). Channels open or close in response to the voltage difference across the membrane, letting potassium ions pass in accordance with their electrochemical gradient. Homotetrameric channels mediate a delayed-rectifier voltage-dependent outward potassium current that display rapid activation and slow inactivation in response to membrane depolarization (PubMed:1550672). Can form functional homotetrameric and heterotetrameric channels that contain variable proportions of KCNB1; channel properties depend on the type of alpha subunits that are part of the channel (PubMed:20202934). Can also form functional heterotetrameric channels with other alpha subunits that are non-conducting when expressed alone, such as KCNS1 and KCNS2, creating a functionally diverse range of channel complexes (PubMed:9305895). In vivo, membranes probably contain a mixture of heteromeric potassium channel complexes, making it difficult to assign currents observed in intact tissues to any particular potassium channel family member. Contributes to the delayed-rectifier voltage-gated potassium current in cortical pyramidal neurons and smooth muscle cells (PubMed:1550672, PubMed:20202934).[UniProtKB:A6H8H5]<ref>PMID:1550672</ref> <ref>PMID:20202934</ref> <ref>PMID:9305895</ref> [https://www.uniprot.org/uniprot/KCNA2_RAT KCNA2_RAT] Mediates the voltage-dependent potassium ion permeability of excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient.<ref>PMID:7544443</ref>  
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Voltage-activated potassium (Kv) channels open to conduct K(+) ions in response to membrane depolarization, and subsequently enter non-conducting states through distinct mechanisms of inactivation. X-ray structures of detergent-solubilized Kv channels appear to have captured an open state even though a non-conducting C-type inactivated state would predominate in membranes in the absence of a transmembrane voltage. However, structures for a voltage-activated ion channel in a lipid bilayer environment have not yet been reported. Here we report the structure of the Kv1.2-2.1 paddle chimera channel reconstituted into lipid nanodiscs using single-particle cryo-electron microscopy. At a resolution of ~3 A for the cytosolic domain and ~4 A for the transmembrane domain, the structure determined in nanodiscs is similar to the previously determined X-ray structure. Our findings show that large differences in structure between detergent and lipid bilayer environments are unlikely, and enable us to propose possible structural mechanisms for C-type inactivation.


Single-particle cryo-EM structure of a voltage-activated potassium channel in lipid nanodiscs.,Matthies D, Bae C, Toombes GE, Fox T, Bartesaghi A, Subramaniam S, Swartz KJ Elife. 2018 Aug 15;7. pii: 37558. doi: 10.7554/eLife.37558. PMID:30109985<ref>PMID:30109985</ref>
==See Also==
 
*[[Potassium channel 3D structures|Potassium channel 3D structures]]
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 6ebm" style="background-color:#fffaf0;"></div>
== References ==
== References ==
<references/>
<references/>
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[[Category: Large Structures]]
[[Category: Large Structures]]
[[Category: Bae, C]]
[[Category: Rattus norvegicus]]
[[Category: Bartesaghi, A]]
[[Category: Bae C]]
[[Category: Fox, T]]
[[Category: Bartesaghi A]]
[[Category: Matthies, D]]
[[Category: Fox T]]
[[Category: Subramaniam, S]]
[[Category: Matthies D]]
[[Category: Swartz, K J]]
[[Category: Subramaniam S]]
[[Category: Lipid nanodisc]]
[[Category: Swartz KJ]]
[[Category: Membrane protein]]
[[Category: Potassium channel]]
[[Category: Transport protein]]

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