6BY2

Closed and deep-inactivated conformation of KcsA-T75A mutant

6BY2 の概要

• エントリーDOI: 10.2210/pdb6by2/pdb
• 分子名称: Antibody Heavy Chain, Antibody Light Chain, pH-gated potassium channel KcsA, ... (7 entities in total)
• 機能のキーワード: kcsa, c-type inactivation, ion channel, potassium channel, membrane protein
• 由来する生物種: Mus musculus; 詳細
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 58682.26

構造登録者

Labro, A.J.,Cortes, D.M.,Tilegenova, C.,Cuello, L.G. (登録日: 2017-12-19, 公開日: 2018-05-09, 最終更新日: 2020-01-01)

主引用文献

Labro, A.J.,Cortes, D.M.,Tilegenova, C.,Cuello, L.G.
Inverted allosteric coupling between activation and inactivation gates in K+channels.
Proc. Natl. Acad. Sci. U.S.A., 115:5426-5431, 2018

PubMed Abstract: The selectivity filter and the activation gate in potassium channels are functionally and structurally coupled. An allosteric coupling underlies C-type inactivation coupled to activation gating in this ion-channel family (i.e., opening of the activation gate triggers the collapse of the channel's selectivity filter). We have identified the second Threonine residue within the TTVGYGD signature sequence of K channels as a crucial residue for this allosteric communication. A Threonine to Alanine substitution at this position was studied in three representative members of the K-channel family. Interestingly, all of the mutant channels exhibited lack of C-type inactivation gating and an inversion of their allosteric coupling (i.e., closing of the activation gate collapses the channel's selectivity filter). A state-dependent crystallographic study of KcsA-T75A proves that, on activation, the selectivity filter transitions from a nonconductive and deep C-type inactivated conformation to a conductive one. Finally, we provide a crystallographic demonstration that closed-state inactivation can be achieved by the structural collapse of the channel's selectivity filter.

PubMed: 29735651
DOI: 10.1073/pnas.1800559115

実験手法

X-RAY DIFFRACTION (2.35 Å)