Novel insights into K+ selectivity from high-resolution structures of an open K+ channel pore

Sheng Ye, Yang Li, Youxing Jiang

Research output: Contribution to journalArticle

94 Citations (Scopus)

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 languageEnglish (US)
Pages (from-to)1019-1023
Number of pages5
JournalNature Structural and Molecular Biology
Volume17
Issue number8
DOIs
StatePublished - Aug 2010

Fingerprint

Ions

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 journalArticle

@article{d276de5362a644eeac71a8056bea201b,
title = "Novel insights into K+ selectivity from high-resolution structures of an open K+ channel pore",
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-{\AA}resolution. 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.",
author = "Sheng Ye and Yang Li and Youxing Jiang",
year = "2010",
month = "8",
doi = "10.1038/nsmb.1865",
language = "English (US)",
volume = "17",
pages = "1019--1023",
journal = "Nature Structural and Molecular Biology",
issn = "1545-9993",
publisher = "Nature Publishing Group",
number = "8",

}

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.

UR - http://www.scopus.com/inward/record.url?scp=77955423895&partnerID=8YFLogxK

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 -