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Structure of a KirBac potassium channel with an open bundle-crossing indicates a mechanism of channel gating

KirBac channels are prokaryotic homologs of mammalian inwardly-rectifying (Kir) potassium channels and recent crystal structures of both Kir and KirBac channels have provided a major insight into their unique structural architecture. However, all of the available structures are closed at the helix b...

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Autores principales: Bavro, Vassiliy N., De Zorzi, Rita, Schmidt, Matthias R., Muniz, Joao R.C., Zubcevic, Lejla, Sansom, Mark S.P., Vénien-Bryan, Catherine, Tucker, Stephen J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3272479/
https://www.ncbi.nlm.nih.gov/pubmed/22231399
http://dx.doi.org/10.1038/nsmb.2208
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author Bavro, Vassiliy N.
De Zorzi, Rita
Schmidt, Matthias R.
Muniz, Joao R.C.
Zubcevic, Lejla
Sansom, Mark S.P.
Vénien-Bryan, Catherine
Tucker, Stephen J.
author_facet Bavro, Vassiliy N.
De Zorzi, Rita
Schmidt, Matthias R.
Muniz, Joao R.C.
Zubcevic, Lejla
Sansom, Mark S.P.
Vénien-Bryan, Catherine
Tucker, Stephen J.
author_sort Bavro, Vassiliy N.
collection PubMed
description KirBac channels are prokaryotic homologs of mammalian inwardly-rectifying (Kir) potassium channels and recent crystal structures of both Kir and KirBac channels have provided a major insight into their unique structural architecture. However, all of the available structures are closed at the helix bundle-crossing and therefore the structural mechanisms that control opening of their primary activation gate remain unknown. In this study, we engineered the inner pore-lining helix (TM2) of KirBac3.1 to trap the bundle-crossing in an apparently open conformation, and determined the crystal structure of this mutant channel to 3.05 Å resolution. Contrary to previous speculation, this novel structure suggests a mechanistic model in which rotational ‘twist’ of the cytoplasmic domain is coupled to opening of the bundle-crossing gate via a network of inter- and intra-subunit interactions that involves the TM2 C-linker, slide-helix, G-loop and the CD-loop.
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spelling pubmed-32724792012-08-01 Structure of a KirBac potassium channel with an open bundle-crossing indicates a mechanism of channel gating Bavro, Vassiliy N. De Zorzi, Rita Schmidt, Matthias R. Muniz, Joao R.C. Zubcevic, Lejla Sansom, Mark S.P. Vénien-Bryan, Catherine Tucker, Stephen J. Nat Struct Mol Biol Article KirBac channels are prokaryotic homologs of mammalian inwardly-rectifying (Kir) potassium channels and recent crystal structures of both Kir and KirBac channels have provided a major insight into their unique structural architecture. However, all of the available structures are closed at the helix bundle-crossing and therefore the structural mechanisms that control opening of their primary activation gate remain unknown. In this study, we engineered the inner pore-lining helix (TM2) of KirBac3.1 to trap the bundle-crossing in an apparently open conformation, and determined the crystal structure of this mutant channel to 3.05 Å resolution. Contrary to previous speculation, this novel structure suggests a mechanistic model in which rotational ‘twist’ of the cytoplasmic domain is coupled to opening of the bundle-crossing gate via a network of inter- and intra-subunit interactions that involves the TM2 C-linker, slide-helix, G-loop and the CD-loop. 2012-01-08 /pmc/articles/PMC3272479/ /pubmed/22231399 http://dx.doi.org/10.1038/nsmb.2208 Text en Users may view, print, copy, download and text and data- mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use: http://www.nature.com/authors/editorial_policies/license.html#terms
spellingShingle Article
Bavro, Vassiliy N.
De Zorzi, Rita
Schmidt, Matthias R.
Muniz, Joao R.C.
Zubcevic, Lejla
Sansom, Mark S.P.
Vénien-Bryan, Catherine
Tucker, Stephen J.
Structure of a KirBac potassium channel with an open bundle-crossing indicates a mechanism of channel gating
title Structure of a KirBac potassium channel with an open bundle-crossing indicates a mechanism of channel gating
title_full Structure of a KirBac potassium channel with an open bundle-crossing indicates a mechanism of channel gating
title_fullStr Structure of a KirBac potassium channel with an open bundle-crossing indicates a mechanism of channel gating
title_full_unstemmed Structure of a KirBac potassium channel with an open bundle-crossing indicates a mechanism of channel gating
title_short Structure of a KirBac potassium channel with an open bundle-crossing indicates a mechanism of channel gating
title_sort structure of a kirbac potassium channel with an open bundle-crossing indicates a mechanism of channel gating
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3272479/
https://www.ncbi.nlm.nih.gov/pubmed/22231399
http://dx.doi.org/10.1038/nsmb.2208
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