3LDC

High resolution open MthK pore structure crystallized in 100 mM K+

3LDC の概要

• エントリーDOI: 10.2210/pdb3ldc/pdb
• 関連するPDBエントリー: 1LNQ 2FY8 3LDD 3LDE
• 分子名称: Calcium-gated potassium channel mthK, POTASSIUM ION (3 entities in total)
• 機能のキーワード: transmembrane, ion channel, open conformation, potassium, ion transport, alternative initiation, cell membrane, ionic channel, membrane, metal-binding, potassium transport, transport protein
• 由来する生物種: Methanothermobacter thermautotrophicus
• 細胞内の位置: Cell membrane; Multi-pass membrane protein: O27564
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 9230.07

構造登録者

Ye, S. (登録日: 2010-01-12, 公開日: 2010-08-11, 最終更新日: 2023-09-06)

主引用文献

Ye, S.,Li, Y.,Jiang, Y.
Novel insights into K(+) selectivity from high-resolution structures of an open K(+) channel pore.
Nat.Struct.Mol.Biol., 17:1019-1023, 2010

PubMed 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-A 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.

PubMed: 20676101
DOI: 10.1038/nsmb.1865

実験手法

X-RAY DIFFRACTION (1.45 Å)