1KPL

Crystal Structure of the ClC Chloride Channel from S. typhimurium

Summary for 1KPL

• Entry DOI: 10.2210/pdb1kpl/pdb
• Related: 1KPK
• Descriptor: putative ClC family, chlorine transport protein, CHLORIDE ION, SULFATE ION, ... (6 entities in total)
• Functional Keywords: helical membrane protein, homodimer, ion channel, membrane protein
• Biological source: Salmonella typhimurium
• Cellular location: Cell inner membrane; Multi-pass membrane protein (Probable): Q8ZRP8
• Total number of polymer chains: 4
• Total formula weight: 203177.70

Authors

Dutzler, R.,Campbell, E.B.,Cadene, M.,Chait, B.T.,MacKinnon, R. (deposition date: 2001-12-31, release date: 2002-01-23, Last modification date: 2024-02-14)

Primary citation

Dutzler, R.,Campbell, E.B.,Cadene, M.,Chait, B.T.,MacKinnon, R.
X-ray structure of a ClC chloride channel at 3.0 A reveals the molecular basis of anion selectivity.
Nature, 415:287-294, 2002

PubMed Abstract: 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.

PubMed: 11796999
DOI: 10.1038/415287a

Experimental method

X-RAY DIFFRACTION (3 Å)