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Structural and functional characterization of a calcium-activated cation channel from Tsukamurella paurometabola

The selectivity filter is an essential functional element of K(+) channels that is highly conserved both in terms of its primary sequence and its three-dimensional structure. Here, we investigate the properties of an ion channel from the Gram-positive bacterium Tsukamurella paurometabola with a sele...

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Autores principales: Dhakshnamoorthy, Balasundaresan, Rohaim, Ahmed, Rui, Huan, Blachowicz, Lydia, Roux, Benoît
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5052707/
https://www.ncbi.nlm.nih.gov/pubmed/27678077
http://dx.doi.org/10.1038/ncomms12753
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author Dhakshnamoorthy, Balasundaresan
Rohaim, Ahmed
Rui, Huan
Blachowicz, Lydia
Roux, Benoît
author_facet Dhakshnamoorthy, Balasundaresan
Rohaim, Ahmed
Rui, Huan
Blachowicz, Lydia
Roux, Benoît
author_sort Dhakshnamoorthy, Balasundaresan
collection PubMed
description The selectivity filter is an essential functional element of K(+) channels that is highly conserved both in terms of its primary sequence and its three-dimensional structure. Here, we investigate the properties of an ion channel from the Gram-positive bacterium Tsukamurella paurometabola with a selectivity filter formed by an uncommon proline-rich sequence. Electrophysiological recordings show that it is a non-selective cation channel and that its activity depends on Ca(2+) concentration. In the crystal structure, the selectivity filter adopts a novel conformation with Ca(2+) ions bound within the filter near the pore helix where they are coordinated by backbone oxygen atoms, a recurrent motif found in multiple proteins. The binding of Ca(2+) ion in the selectivity filter controls the widening of the pore as shown in crystal structures and in molecular dynamics simulations. The structural, functional and computational data provide a characterization of this calcium-gated cationic channel.
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spelling pubmed-50527072016-10-21 Structural and functional characterization of a calcium-activated cation channel from Tsukamurella paurometabola Dhakshnamoorthy, Balasundaresan Rohaim, Ahmed Rui, Huan Blachowicz, Lydia Roux, Benoît Nat Commun Article The selectivity filter is an essential functional element of K(+) channels that is highly conserved both in terms of its primary sequence and its three-dimensional structure. Here, we investigate the properties of an ion channel from the Gram-positive bacterium Tsukamurella paurometabola with a selectivity filter formed by an uncommon proline-rich sequence. Electrophysiological recordings show that it is a non-selective cation channel and that its activity depends on Ca(2+) concentration. In the crystal structure, the selectivity filter adopts a novel conformation with Ca(2+) ions bound within the filter near the pore helix where they are coordinated by backbone oxygen atoms, a recurrent motif found in multiple proteins. The binding of Ca(2+) ion in the selectivity filter controls the widening of the pore as shown in crystal structures and in molecular dynamics simulations. The structural, functional and computational data provide a characterization of this calcium-gated cationic channel. Nature Publishing Group 2016-09-28 /pmc/articles/PMC5052707/ /pubmed/27678077 http://dx.doi.org/10.1038/ncomms12753 Text en Copyright © 2016, The Author(s) http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
spellingShingle Article
Dhakshnamoorthy, Balasundaresan
Rohaim, Ahmed
Rui, Huan
Blachowicz, Lydia
Roux, Benoît
Structural and functional characterization of a calcium-activated cation channel from Tsukamurella paurometabola
title Structural and functional characterization of a calcium-activated cation channel from Tsukamurella paurometabola
title_full Structural and functional characterization of a calcium-activated cation channel from Tsukamurella paurometabola
title_fullStr Structural and functional characterization of a calcium-activated cation channel from Tsukamurella paurometabola
title_full_unstemmed Structural and functional characterization of a calcium-activated cation channel from Tsukamurella paurometabola
title_short Structural and functional characterization of a calcium-activated cation channel from Tsukamurella paurometabola
title_sort structural and functional characterization of a calcium-activated cation channel from tsukamurella paurometabola
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5052707/
https://www.ncbi.nlm.nih.gov/pubmed/27678077
http://dx.doi.org/10.1038/ncomms12753
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