3ogc: Difference between revisions
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[[ | ==KcsA E71A variant in presence of Na+== | ||
<StructureSection load='3ogc' size='340' side='right' caption='[[3ogc]], [[Resolution|resolution]] 3.80Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3ogc]] is a 3 chain structure with sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] and [http://en.wikipedia.org/wiki/Streptomyces_lividans Streptomyces lividans]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3OGC OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3OGC FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=NA:SODIUM+ION'>NA</scene></td></tr> | |||
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">kcsA, skc1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1916 Streptomyces lividans])</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=3ogc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3ogc OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3ogc RCSB], [http://www.ebi.ac.uk/pdbsum/3ogc PDBsum]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Structures of the prokaryotic K(+) channel, KcsA, highlight the role of the selectivity filter carbonyls from the GYG signature sequence in determining a highly selective pore, but channels displaying this sequence vary widely in their cation selectivity. Furthermore, variable selectivity can be found within the same channel during a process called C-type inactivation. We investigated the mechanism for changes in selectivity associated with inactivation in a model K(+) channel, KcsA. We found that E71A, a noninactivating KcsA mutant in which a hydrogen-bond behind the selectivity filter is disrupted, also displays decreased K(+) selectivity. In E71A channels, Na(+) permeates at higher rates as seen with and flux measurements and analysis of intracellular Na(+) block. Crystal structures of E71A reveal that the selectivity filter no longer assumes the "collapsed," presumed inactivated, conformation in low K(+), but a "flipped" conformation, that is also observed in high K(+), high Na(+), and even Na(+) only conditions. The data reveal the importance of the E71-D80 interaction in both favoring inactivation and maintaining high K(+) selectivity. We propose a molecular mechanism by which inactivation and K(+) selectivity are linked, a mechanism that may also be at work in other channels containing the canonical GYG signature sequence. | |||
Mechanism for selectivity-inactivation coupling in KcsA potassium channels.,Cheng WW, McCoy JG, Thompson AN, Nichols CG, Nimigean CM Proc Natl Acad Sci U S A. 2011 Mar 29;108(13):5272-7. Epub 2011 Mar 14. PMID:21402935<ref>PMID:21402935</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[Antibody|Antibody]] | *[[Antibody|Antibody]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Mus musculus]] | [[Category: Mus musculus]] | ||
[[Category: Streptomyces lividans]] | [[Category: Streptomyces lividans]] | ||
[[Category: McCoy, J G | [[Category: McCoy, J G]] | ||
[[Category: Nimigean, C M | [[Category: Nimigean, C M]] | ||
[[Category: Antibody fab complex]] | [[Category: Antibody fab complex]] | ||
[[Category: Membrane protein]] | [[Category: Membrane protein]] | ||
[[Category: Voltage-gated channel]] | [[Category: Voltage-gated channel]] | ||
