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2ahz
From Proteopedia
| Line 4: | Line 4: | ||
|PDB= 2ahz |SIZE=350|CAPTION= <scene name='initialview01'>2ahz</scene>, resolution 2.80Å | |PDB= 2ahz |SIZE=350|CAPTION= <scene name='initialview01'>2ahz</scene>, resolution 2.80Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand= | + | |LIGAND= <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[2ahy|2AHY]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2ahz FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ahz OCA], [http://www.ebi.ac.uk/pdbsum/2ahz PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=2ahz RCSB]</span> | ||
}} | }} | ||
| Line 27: | Line 30: | ||
[[Category: Shi, N.]] | [[Category: Shi, N.]] | ||
[[Category: Ye, S.]] | [[Category: Ye, S.]] | ||
| - | [[Category: CA]] | ||
| - | [[Category: K]] | ||
[[Category: central cavity]] | [[Category: central cavity]] | ||
[[Category: helix bundle]] | [[Category: helix bundle]] | ||
| Line 35: | Line 36: | ||
[[Category: tetramer]] | [[Category: tetramer]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 01:52:58 2008'' |
Revision as of 22:52, 30 March 2008
| |||||||
| , resolution 2.80Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , | ||||||
| Related: | 2AHY
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
K+ complex of the NaK Channel
Overview
Ion selectivity is one of the basic properties that define an ion channel. Most tetrameric cation channels, which include the K+, Ca2+, Na+ and cyclic nucleotide-gated channels, probably share a similar overall architecture in their ion-conduction pore, but the structural details that determine ion selection are different. Although K+ channel selectivity has been well studied from a structural perspective, little is known about the structure of other cation channels. Here we present crystal structures of the NaK channel from Bacillus cereus, a non-selective tetrameric cation channel, in its Na+- and K+-bound states at 2.4 A and 2.8 A resolution, respectively. The NaK channel shares high sequence homology and a similar overall structure with the bacterial KcsA K+ channel, but its selectivity filter adopts a different architecture. Unlike a K+ channel selectivity filter, which contains four equivalent K+-binding sites, the selectivity filter of the NaK channel preserves the two cation-binding sites equivalent to sites 3 and 4 of a K+ channel, whereas the region corresponding to sites 1 and 2 of a K+ channel becomes a vestibule in which ions can diffuse but not bind specifically. Functional analysis using an 86Rb flux assay shows that the NaK channel can conduct both Na+ and K+ ions. We conclude that the sequence of the NaK selectivity filter resembles that of a cyclic nucleotide-gated channel and its structure may represent that of a cyclic nucleotide-gated channel pore.
About this Structure
2AHZ is a Single protein structure of sequence from Bacillus cereus. Full crystallographic information is available from OCA.
Reference
Atomic structure of a Na+- and K+-conducting channel., Shi N, Ye S, Alam A, Chen L, Jiang Y, Nature. 2006 Mar 23;440(7083):570-4. Epub 2006 Feb 8. PMID:16467789
Page seeded by OCA on Mon Mar 31 01:52:58 2008
Categories: Bacillus cereus | Single protein | Alam, A. | Chen, L. | Jiang, Y. | Shi, N. | Ye, S. | Central cavity | Helix bundle | Inverted teepee | Ion binding | Tetramer
