5KJ3

Connexin 26 WT peptide NMR Structure

5KJ3 の概要

• エントリーDOI: 10.2210/pdb5kj3/pdb
• NMR情報: BMRB: 30119
• 分子名称: Gap junction beta-2 protein (1 entity in total)
• 機能のキーワード: connexin26 nmr structure peptide, transport protein
• 由来する生物種: Homo sapiens (Human)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 2372.72

構造登録者

Dowd, T.L.,Bargiello, T.A. (登録日: 2016-06-17, 公開日: 2016-09-28, 最終更新日: 2024-11-20)

主引用文献

Batir, Y.,Bargiello, T.A.,Dowd, T.L.
Structural studies of N-terminal mutants of Connexin 26 and Connexin 32 using (1)H NMR spectroscopy.
Arch.Biochem.Biophys., 608:8-19, 2016

PubMed Abstract: Alterations in gap junctions underlie the etiologies of syndromic deafness (KID) and Charcot-Marie Tooth disease (CMTX). Functional gap junctions are composed of connexin molecules with N-termini containing a flexible turn around G12, inserting the N-termini into the channel pore allowing voltage gating. The loss of this turn correlates with loss of Connexin 32 (Cx32) function by impaired trafficking to the cell membrane. Using (1)H NMR we show the N-terminus of a syndromic deafness mutation Cx26G12R, producing "leaky channels", contains a turn around G12 which is less structured and more flexible than wild-type. In contrast, the N-terminal structure of the same mutation in Cx32 chimera, Cx32*43E1G12R shows a larger constricted turn and no membrane current expression but forms membrane inserted hemichannels. Their function was rescued by formation of heteromeric channels with wild type subunits. We suggest the inflexible Cx32G12R N-terminus blocks ion conduction in homomeric channels and this channel block is relieved by incorporation of wild type subunits. In contrast, the increased open probability of Cx26G12R hemichannels is likely due to the addition of positive charge in the channel pore changing pore electrostatics and impairing hemichannel regulation by Ca(2+). These results provide mechanistic information on aberrant channel activity observed in disease.

PubMed: 27378082
DOI: 10.1016/j.abb.2016.06.019

実験手法

SOLUTION NMR