2H2P: Crystal Structure Of Clc-ec1 In Complex With Fab Fragment In Secn-

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.
PDB ID: 2H2PDownload
MMDB ID: 39499
PDB Deposition Date: 2006/5/19
Updated in MMDB: 2012/12
Experimental Method:
x-ray diffraction
Resolution: 3.1  Å
Source Organism:
Mus musculus
Similar Structures:
Biological Unit for 2H2P: hexameric; determined by author
Molecular Components in 2H2P
Label Count Molecule
Proteins (6 molecules)
CLC CL Transporter(Gene symbol: clcA)
Molecule annotation
FAB Fragment, Heavy Chain
Molecule annotation
FAB Fragment, Light Chain
Molecule annotation
Chemicals (8 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB