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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...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
2012
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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. |
format | Online Article Text |
id | pubmed-3272479 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2012 |
record_format | MEDLINE/PubMed |
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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