Abstract
K+ channels are highly selective for K+ over Na +. Here we present several crystal structures of the MthK K + channel pore at up to 1.45-Åresolution. The MthK selectivity filter maintains a conductive conformation even in the absence of K+, allowing the channel to conduct Na+. The high-resolution structures, along with single-channel recordings, allow for an accurate analysis of how K+ competes with Na+ in a conductive selectivity filter. At high K+ concentrations, two K+ ions equivalently occupy the four sites in the selectivity filter, whereas at low K+/high Na+ concentrations, a single K+ ion remains bound in the selectivity filter, preferably at site 1 or site 3. This single K+ binding at low concentration effectively blocks the permeation of Na +, providing a structural basis for the anomalous mole-fraction effect, a key property of multi-ion pores.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1019-1023 |
| Number of pages | 5 |
| Journal | Nature Structural and Molecular Biology |
| Volume | 17 |
| Issue number | 8 |
| DOIs | |
| State | Published - Aug 2010 |
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ASJC Scopus subject areas
- Structural Biology
- Molecular Biology
Cite this
Novel insights into K+ selectivity from high-resolution structures of an open K+ channel pore. / Ye, Sheng; Li, Yang; Jiang, Youxing.
In: Nature Structural and Molecular Biology, Vol. 17, No. 8, 08.2010, p. 1019-1023.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Novel insights into K+ selectivity from high-resolution structures of an open K+ channel pore
AU - Ye, Sheng
AU - Li, Yang
AU - Jiang, Youxing
PY - 2010/8
Y1 - 2010/8
N2 - K+ channels are highly selective for K+ over Na +. Here we present several crystal structures of the MthK K + channel pore at up to 1.45-Åresolution. The MthK selectivity filter maintains a conductive conformation even in the absence of K+, allowing the channel to conduct Na+. The high-resolution structures, along with single-channel recordings, allow for an accurate analysis of how K+ competes with Na+ in a conductive selectivity filter. At high K+ concentrations, two K+ ions equivalently occupy the four sites in the selectivity filter, whereas at low K+/high Na+ concentrations, a single K+ ion remains bound in the selectivity filter, preferably at site 1 or site 3. This single K+ binding at low concentration effectively blocks the permeation of Na +, providing a structural basis for the anomalous mole-fraction effect, a key property of multi-ion pores.
AB - K+ channels are highly selective for K+ over Na +. Here we present several crystal structures of the MthK K + channel pore at up to 1.45-Åresolution. The MthK selectivity filter maintains a conductive conformation even in the absence of K+, allowing the channel to conduct Na+. The high-resolution structures, along with single-channel recordings, allow for an accurate analysis of how K+ competes with Na+ in a conductive selectivity filter. At high K+ concentrations, two K+ ions equivalently occupy the four sites in the selectivity filter, whereas at low K+/high Na+ concentrations, a single K+ ion remains bound in the selectivity filter, preferably at site 1 or site 3. This single K+ binding at low concentration effectively blocks the permeation of Na +, providing a structural basis for the anomalous mole-fraction effect, a key property of multi-ion pores.
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UR - http://www.scopus.com/inward/citedby.url?scp=77955423895&partnerID=8YFLogxK
U2 - 10.1038/nsmb.1865
DO - 10.1038/nsmb.1865
M3 - Article
VL - 17
SP - 1019
EP - 1023
JO - Nature Structural and Molecular Biology
JF - Nature Structural and Molecular Biology
SN - 1545-9993
IS - 8
ER -