1k4c
From Proteopedia
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[[Image:1k4c.gif|left|200px]] | [[Image:1k4c.gif|left|200px]] | ||
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'''Potassium Channel KcsA-Fab complex in high concentration of K+''' | '''Potassium Channel KcsA-Fab complex in high concentration of K+''' | ||
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[[Category: Morais-Cabral, J H.]] | [[Category: Morais-Cabral, J H.]] | ||
[[Category: Zhou, Y.]] | [[Category: Zhou, Y.]] | ||
- | [[Category: | + | [[Category: K channel]] |
- | [[Category: | + | [[Category: Protein-antibody fab complex]] |
- | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 22:17:28 2008'' | |
- | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + |
Revision as of 19:17, 2 May 2008
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1k4c, resolution 2.00Å () | |||||||||
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Ligands: | , , | ||||||||
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Resources: | FirstGlance, OCA, RCSB, PDBsum | ||||||||
Coordinates: | save as pdb, mmCIF, xml |
Potassium Channel KcsA-Fab complex in high concentration of K+
Overview
Ion transport proteins must remove an ion's hydration shell to coordinate the ion selectively on the basis of its size and charge. To discover how the K+ channel solves this fundamental aspect of ion conduction, we solved the structure of the KcsA K+ channel in complex with a monoclonal Fab antibody fragment at 2.0 A resolution. Here we show how the K+ channel displaces water molecules around an ion at its extracellular entryway, and how it holds a K+ ion in a square antiprism of water molecules in a cavity near its intracellular entryway. Carbonyl oxygen atoms within the selectivity filter form a very similar square antiprism around each K+ binding site, as if to mimic the waters of hydration. The selectivity filter changes its ion coordination structure in low K+ solutions. This structural change is crucial to the operation of the selectivity filter in the cellular context, where the K+ ion concentration near the selectivity filter varies in response to channel gating.
About this Structure
1K4C is a Single protein structure of sequence from Mus musculus and Streptomyces lividans. The following page contains interesting information on the relation of 1K4C with [Potassium Channels]. Full crystallographic information is available from OCA.
Reference
Chemistry of ion coordination and hydration revealed by a K+ channel-Fab complex at 2.0 A resolution., Zhou Y, Morais-Cabral JH, Kaufman A, MacKinnon R, Nature. 2001 Nov 1;414(6859):43-8. PMID:11689936 Page seeded by OCA on Fri May 2 22:17:28 2008