1jvm: Difference between revisions

Revision as of 14:27, 21 February 2008

KCSA POTASSIUM CHANNEL WITH TBA (TETRABUTYLAMMONIUM) AND RUBIDIUM

OverviewOverview

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.

About this StructureAbout this Structure

1JVM is a Single protein structure of sequence from Streptomyces lividans with and as ligands. Full crystallographic information is available from OCA.

ReferenceReference

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

Page seeded by OCA on Thu Feb 21 13:27:19 2008

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OCA

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-[[Image:1jvm.gif|left|200px]]<br /><applet load="1jvm" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1jvm.gif|left|200px]]<br /><applet load="1jvm" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1jvm, resolution 2.8&Aring;" />
 '''KCSA POTASSIUM CHANNEL WITH TBA (TETRABUTYLAMMONIUM) AND RUBIDIUM'''<br />
 ==Overview==
-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.
+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.
 ==About this Structure==
-JVM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptomyces_lividans Streptomyces lividans] with RB and TBA as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1JVM OCA].
+JVM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptomyces_lividans Streptomyces lividans] with <scene name='pdbligand=RB:'>RB</scene> and <scene name='pdbligand=TBA:'>TBA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JVM OCA].
 ==Reference==
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 [[Category: Streptomyces lividans]]
 [[Category: MacKinnon, R.]]
-[[Category: Morais-Cabral, J.H.]]
+[[Category: Morais-Cabral, J H.]]
 [[Category: Zhou, Y.]]
 [[Category: RB]]
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 [[Category: potassium channel]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 18:36:45 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:27:19 2008''