2H2P

Crystal structure of CLC-ec1 in complex with Fab fragment in SeCN-

Summary for 2H2P

• Entry DOI: 10.2210/pdb2h2p/pdb
• Related: 1OTS 2H2S
• Descriptor: CLC Cl transporter, FAB fragment, heavy chain, FAB fragment, light chain, ... (4 entities in total)
• Functional Keywords: clc; transporter; chloride; antiport, ion transport
• Biological source: Escherichia coli; More
• Cellular location: Cell inner membrane ; Multi- pass membrane protein : P37019
• Total number of polymer chains: 6
• Total formula weight: 193721.93

Authors

Nguitragool, W.,Miller, C. (deposition date: 2006-05-19, release date: 2006-05-30, Last modification date: 2024-10-16)

Primary citation

Nguitragool, W.,Miller, C.
Uncoupling of a CLC Cl(-)/H(+) Exchange Transporter by Polyatomic Anions
J.Mol.Biol., 362:682-690, 2006

PubMed Abstract: 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.

PubMed: 16905147
DOI: 10.1016/j.jmb.2006.07.006

Experimental method

X-RAY DIFFRACTION (3.1 Å)