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1jvm
From Proteopedia
| 1jvm, resolution 2.80Å () | |||||||||
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| Ligands: | , | ||||||||
| Domains: | Ion_trans_2 | ||||||||
| Related: | 1j95, 1bl8 | ||||||||
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||
KCSA POTASSIUM CHANNEL WITH TBA (TETRABUTYLAMMONIUM) AND RUBIDIUM
The K+ selectivity filter catalyses the dehydration, transfer and rehydration of a K+ ion in about ten nanoseconds. This physical process is central to the production of electrical signals in biology. Here we show how nearly diffusion-limited rates are achieved, by analysing ion conduction and the corresponding crystallographic ion distribution in the selectivity filter of the KcsA K+ channel. Measurements with K+ and its slightly larger analogue, Rb+, lead us to conclude that the selectivity filter usually contains two K+ ions separated by one water molecule. The two ions move in a concerted fashion between two configurations, K+-water-K+-water (1,3 configuration) and water-K+-water-K+ (2,4 configuration), until a third ion enters, displacing the ion on the opposite side of the queue. For K+, the energy difference between the 1,3 and 2,4 configurations is close to zero, the condition of maximum conduction rate. The energetic balance between these configurations is a clear example of evolutionary optimization of protein function.
Energetic optimization of ion conduction rate by the K+ selectivity filter., Morais-Cabral JH, Zhou Y, MacKinnon R, Nature. 2001 Nov 1;414(6859):37-42. PMID:11689935
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this Structure
1JVM is a 4 chains structure of sequences from Streptomyces lividans. Full crystallographic information is available from OCA.
Reference
- Morais-Cabral JH, Zhou Y, MacKinnon R. Energetic optimization of ion conduction rate by the K+ selectivity filter. Nature. 2001 Nov 1;414(6859):37-42. PMID:11689935 doi:10.1038/35102000
Page seeded by OCA on Tue Feb 17 12:22:58 2009
