The Barium Site in a Potassium Channel by X-Ray Crystallography
X-ray diffraction data were collected from frozen crystals (100°K) of the KcsA K+ channel equilibrated with solutions containing barium chloride. Difference electron density maps (Fbarium − Fnative, 5.0 Å resolution) show that Ba2+ resides at a single location within the selectivity filter. The Ba2+...
| Main Authors: | , |
|---|---|
| Format: | Online |
| Language: | English |
| Published: |
The Rockefeller University Press
2000
|
| Online Access: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2217209/ |
| id |
pubmed-2217209 |
|---|---|
| recordtype |
oai_dc |
| spelling |
pubmed-22172092008-04-21 The Barium Site in a Potassium Channel by X-Ray Crystallography Jiang, Youxing MacKinnon, Roderick Original Article X-ray diffraction data were collected from frozen crystals (100°K) of the KcsA K+ channel equilibrated with solutions containing barium chloride. Difference electron density maps (Fbarium − Fnative, 5.0 Å resolution) show that Ba2+ resides at a single location within the selectivity filter. The Ba2+ blocking site corresponds to the internal aspect (adjacent to the central cavity) of the “inner ion” position where an alkali metal cation is found in the absence of the blocking Ba2+ ion. The location of Ba2+ with respect to Rb+ ions in the pore is in good agreement with the findings on the functional interaction of Ba2+ with K+ (and Rb+) in Ca2+-activated K+ channels (Neyton, J., and C. Miller. 1988. J. Gen. Physiol. 92:549–567). Taken together, these structural and functional data imply that at physiological ion concentrations a third ion may interact with two ions in the selectivity filter, perhaps by entering from one side and displacing an ion on the opposite side. The Rockefeller University Press 2000-03-01 /pmc/articles/PMC2217209/ /pubmed/10694255 Text en © 2000 The Rockefeller University Press This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/). |
| repository_type |
Open Access Journal |
| institution_category |
Foreign Institution |
| institution |
US National Center for Biotechnology Information |
| building |
NCBI PubMed |
| collection |
Online Access |
| language |
English |
| format |
Online |
| author |
Jiang, Youxing MacKinnon, Roderick |
| spellingShingle |
Jiang, Youxing MacKinnon, Roderick The Barium Site in a Potassium Channel by X-Ray Crystallography |
| author_facet |
Jiang, Youxing MacKinnon, Roderick |
| author_sort |
Jiang, Youxing |
| title |
The Barium Site in a Potassium Channel by X-Ray Crystallography |
| title_short |
The Barium Site in a Potassium Channel by X-Ray Crystallography |
| title_full |
The Barium Site in a Potassium Channel by X-Ray Crystallography |
| title_fullStr |
The Barium Site in a Potassium Channel by X-Ray Crystallography |
| title_full_unstemmed |
The Barium Site in a Potassium Channel by X-Ray Crystallography |
| title_sort |
barium site in a potassium channel by x-ray crystallography |
| description |
X-ray diffraction data were collected from frozen crystals (100°K) of the KcsA K+ channel equilibrated with solutions containing barium chloride. Difference electron density maps (Fbarium − Fnative, 5.0 Å resolution) show that Ba2+ resides at a single location within the selectivity filter. The Ba2+ blocking site corresponds to the internal aspect (adjacent to the central cavity) of the “inner ion” position where an alkali metal cation is found in the absence of the blocking Ba2+ ion. The location of Ba2+ with respect to Rb+ ions in the pore is in good agreement with the findings on the functional interaction of Ba2+ with K+ (and Rb+) in Ca2+-activated K+ channels (Neyton, J., and C. Miller. 1988. J. Gen. Physiol. 92:549–567). Taken together, these structural and functional data imply that at physiological ion concentrations a third ion may interact with two ions in the selectivity filter, perhaps by entering from one side and displacing an ion on the opposite side. |
| publisher |
The Rockefeller University Press |
| publishDate |
2000 |
| url |
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2217209/ |
| _version_ |
1611435590764462080 |