View source for 1kpk

[[Image:1kpk.gif|left|200px]]

 {{Structure
|PDB= 1kpk |SIZE=350|CAPTION= <scene name='initialview01'>1kpk</scene>, resolution 3.50&Aring;
|SITE= 
|LIGAND= 
|ACTIVITY= 
|GENE= yadQ ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli])
|DOMAIN=
|RELATEDENTRY=[[1kpl|1KPL]]
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1kpk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1kpk OCA], [http://www.ebi.ac.uk/pdbsum/1kpk PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1kpk RCSB]</span>
}}

'''Crystal Structure of the ClC Chloride Channel from E. coli'''


==Overview==
The ClC chloride channels catalyse the selective flow of Cl- ions across cell membranes, thereby regulating electrical excitation in skeletal muscle and the flow of salt and water across epithelial barriers. Genetic defects in ClC Cl- channels underlie several familial muscle and kidney diseases. Here we present the X-ray structures of two prokaryotic ClC Cl- channels from Salmonella enterica serovar typhimurium and Escherichia coli at 3.0 and 3.5 A, respectively. Both structures reveal two identical pores, each pore being formed by a separate subunit contained within a homodimeric membrane protein. Individual subunits are composed of two roughly repeated halves that span the membrane with opposite orientations. This antiparallel architecture defines a selectivity filter in which a Cl- ion is stabilized by electrostatic interactions with alpha-helix dipoles and by chemical coordination with nitrogen atoms and hydroxyl groups. These findings provide a structural basis for further understanding the function of ClC Cl- channels, and establish the physical and chemical basis of their anion selectivity.

==About this Structure==
1KPK is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KPK OCA]. 

==Reference==
X-ray structure of a ClC chloride channel at 3.0 A reveals the molecular basis of anion selectivity., Dutzler R, Campbell EB, Cadene M, Chait BT, MacKinnon R, Nature. 2002 Jan 17;415(6869):287-94. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/11796999 11796999]
[[Category: Escherichia coli]]
[[Category: Single protein]]
[[Category: Cadene, M.]]
[[Category: Campbell, E B.]]
[[Category: Chait, B T.]]
[[Category: Dutzler, R.]]
[[Category: MacKinnon, R.]]
[[Category: helical membrane protein]]
[[Category: homodimer]]

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