1S5H

Potassium Channel Kcsa-Fab Complex T75C mutant in K+

1S5H の概要

• エントリーDOI: 10.2210/pdb1s5h/pdb
• 分子名称: ANTIBODY FAB FRAGMENT LIGHT CHAIN, ANTIBODY FAB FRAGMENT HEAVY CHAIN, Voltage-gated potassium channel, ... (7 entities in total)
• 機能のキーワード: k+ channel, protein-antibody fab complex, selectivity filter, ion occupancy, membrane protein
• 由来する生物種: Streptomyces coelicolor, Streptomyces lividans (,); 詳細
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 61113.57

構造登録者

Mackinnon, R.,Zhou, M. (登録日: 2004-01-20, 公開日: 2004-05-18, 最終更新日: 2024-11-20)

主引用文献

Zhou, M.,MacKinnon, R.
A mutant KcsA K(+) channel with altered conduction properties and selectivity filter ion distribution.
J.Mol.Biol., 338:839-846, 2004

PubMed Abstract: The selectivity filter of K(+) channels is comprised of a linear queue of four equal-spaced ion-binding sites spanning a distance of 12A. Each site is formed of eight oxygen atoms from the protein. The first three sites, numbered 1-3 from the extracellular side, are made of exclusively main-chain carbonyl oxygen atoms. The fourth site, closest to the intracellular side, is made of four main-chain carbonyl oxygen atoms and four threonine side-chain hydroxyl oxygen atoms. Here we characterize the effects of mutating the threonine to cysteine on the distribution of ions in the selectivity filter and on the conduction of ions through the filter. The mutation influences the occupancy of K(+) at sites 2 and 4 and it reduces the maximum rate of conduction in the limit of high K(+) concentration. The mutation does not affect the conduction of Rb(+). These results can be understood in the context of a conduction mechanism in which a pair of K ions switch between energetically balanced 1,3 and 2,4 configurations.

PubMed: 15099749
DOI: 10.1016/j.jmb.2004.03.020

実験手法

X-RAY DIFFRACTION (2.2 Å)