This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1k4c
From Proteopedia
(New page: 200px<br /> <applet load="1k4c" size="450" color="white" frame="true" align="right" spinBox="true" caption="1k4c, resolution 2.00Å" /> '''Potassium Channel K...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1k4c.gif|left|200px]]<br /> | + | [[Image:1k4c.gif|left|200px]]<br /><applet load="1k4c" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="1k4c" size=" | + | |
caption="1k4c, resolution 2.00Å" /> | caption="1k4c, resolution 2.00Å" /> | ||
'''Potassium Channel KcsA-Fab complex in high concentration of K+'''<br /> | '''Potassium Channel KcsA-Fab complex in high concentration of K+'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Ion transport proteins must remove an ion's hydration shell to coordinate | + | 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== | ==About this Structure== | ||
| - | 1K4C 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, DGA and F09 as [http://en.wikipedia.org/wiki/ligands ligands]. The following page contains interesting information on the relation of 1K4C with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb38_1.html Potassium Channels]]. Full crystallographic information is available from [http:// | + | 1K4C 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>, <scene name='pdbligand=DGA:'>DGA</scene> and <scene name='pdbligand=F09:'>F09</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. The following page contains interesting information on the relation of 1K4C with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb38_1.html Potassium Channels]]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1K4C OCA]. |
==Reference== | ==Reference== | ||
| Line 18: | Line 17: | ||
[[Category: Kaufman, A.]] | [[Category: Kaufman, A.]] | ||
[[Category: MacKinnon, R.]] | [[Category: MacKinnon, R.]] | ||
| - | [[Category: Morais-Cabral, J | + | [[Category: Morais-Cabral, J H.]] |
[[Category: Zhou, Y.]] | [[Category: Zhou, Y.]] | ||
[[Category: DGA]] | [[Category: DGA]] | ||
| Line 26: | Line 25: | ||
[[Category: protein-antibody fab complex]] | [[Category: protein-antibody fab complex]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:30:01 2008'' |
Revision as of 11:30, 21 February 2008
|
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 with , and as ligands. 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 Thu Feb 21 13:30:01 2008
