2h2s
Crystal Structure of E148A mutant of CLC-ec1 in SeCN-
OverviewOverview
CLC-ec1 is a bacterial archetype of CLC transporters, a ubiquitous class of proteins that catalyze transmembrane exchange of Cl- and H+ necessary for pH regulation of numerous physiological processes. Despite a profusion of high-resolution structures, the molecular mechanism of exchange remains unknown. Here, we rigorously demonstrate strict exchange stoichiometry of 2 Cl-/1 H+. In addition to Cl- and Br-, two non-halide ions, NO3- and SCN-, are shown to be transported by CLC-ec1, but with reduced H+ counter-transport. The loss of proton coupling to these anions is accompanied by an absence of bound anions in the central and external Cl- binding sites in the protein's anion selectivity region, as revealed by crystallographic comparison of Br- and SeCN- bound to this region.
About this StructureAbout this Structure
2H2S is a Single protein structure of sequence from Escherichia coli and Mus musculus. Full crystallographic information is available from OCA.
ReferenceReference
Uncoupling of a CLC Cl-/H+ exchange transporter by polyatomic anions., Nguitragool W, Miller C, J Mol Biol. 2006 Sep 29;362(4):682-90. Epub 2006 Aug 14. PMID:16905147 Page seeded by OCA on Sun May 4 05:48:09 2008