2ih3
From Proteopedia
(New page: 200px<br /><applet load="2ih3" size="450" color="white" frame="true" align="right" spinBox="true" caption="2ih3, resolution 1.72Å" /> '''Ion selectivity in a...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:2ih3.gif|left|200px]]<br /><applet load="2ih3" size=" | + | [[Image:2ih3.gif|left|200px]]<br /><applet load="2ih3" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2ih3, resolution 1.72Å" /> | caption="2ih3, resolution 1.72Å" /> | ||
'''Ion selectivity in a semi-synthetic K+ channel locked in the conductive conformation'''<br /> | '''Ion selectivity in a semi-synthetic K+ channel locked in the conductive conformation'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Potassium channels are K+-selective protein pores in cell membrane. The | + | Potassium channels are K+-selective protein pores in cell membrane. The selectivity filter is the functional unit that allows K+ channels to distinguish potassium (K+) and sodium (Na+) ions. The filter's structure depends on whether K+ or Na+ ions are bound inside it. We synthesized a K+ channel containing the d-enantiomer of alanine in place of a conserved glycine and found by x-ray crystallography that its filter maintains the K+ (conductive) structure in the presence of Na+ and very low concentrations of K+. This channel conducts Na+ in the absence of K+ but not in the presence of K+. These findings demonstrate that the ability of the channel to adapt its structure differently to K+ and Na+ is a fundamental aspect of ion selectivity, as is the ability of multiple K+ ions to compete effectively with Na+ for the conductive filter. |
==About this Structure== | ==About this Structure== | ||
| - | 2IH3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] and [http://en.wikipedia.org/wiki/Streptomyces_lividans Streptomyces lividans] with K and 1EM as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 2IH3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] and [http://en.wikipedia.org/wiki/Streptomyces_lividans Streptomyces lividans] with <scene name='pdbligand=K:'>K</scene> and <scene name='pdbligand=1EM:'>1EM</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2IH3 OCA]. |
==Reference== | ==Reference== | ||
| Line 16: | Line 16: | ||
[[Category: Leonetti, M.]] | [[Category: Leonetti, M.]] | ||
[[Category: MacKinnon, R.]] | [[Category: MacKinnon, R.]] | ||
| - | [[Category: Muir, T | + | [[Category: Muir, T W.]] |
| - | [[Category: Valiyaveetil, F | + | [[Category: Valiyaveetil, F I.]] |
[[Category: 1EM]] | [[Category: 1EM]] | ||
[[Category: K]] | [[Category: K]] | ||
[[Category: ion channel d-amino acid semi-synthetic]] | [[Category: ion channel d-amino acid semi-synthetic]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:52:36 2008'' |
Revision as of 15:52, 21 February 2008
|
Ion selectivity in a semi-synthetic K+ channel locked in the conductive conformation
Overview
Potassium channels are K+-selective protein pores in cell membrane. The selectivity filter is the functional unit that allows K+ channels to distinguish potassium (K+) and sodium (Na+) ions. The filter's structure depends on whether K+ or Na+ ions are bound inside it. We synthesized a K+ channel containing the d-enantiomer of alanine in place of a conserved glycine and found by x-ray crystallography that its filter maintains the K+ (conductive) structure in the presence of Na+ and very low concentrations of K+. This channel conducts Na+ in the absence of K+ but not in the presence of K+. These findings demonstrate that the ability of the channel to adapt its structure differently to K+ and Na+ is a fundamental aspect of ion selectivity, as is the ability of multiple K+ ions to compete effectively with Na+ for the conductive filter.
About this Structure
2IH3 is a Single protein structure of sequence from Mus musculus and Streptomyces lividans with and as ligands. Full crystallographic information is available from OCA.
Reference
Ion selectivity in a semisynthetic K+ channel locked in the conductive conformation., Valiyaveetil FI, Leonetti M, Muir TW, Mackinnon R, Science. 2006 Nov 10;314(5801):1004-7. PMID:17095703
Page seeded by OCA on Thu Feb 21 17:52:36 2008
