Uncoupling of a CLC Cl-/H+ exchange transporter by polyatomic anions

Nguitragool, W; Miller, C

doi:10.1016/j.jmb.2006.07.006

Title: Uncoupling of a CLC Cl-/H+ exchange transporter by polyatomic anions

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Abstract

CLC-ec1 is a bacterial archetype of CLC transporters, a ubiquitous class of proteins that catalyze transmembrane exchange of Cl{sup -} and H{sup +} 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{sup -}/1 H{sup +}. In addition to Cl{sup -} and Br{sup -}, two non-halide ions, NO{sub 3}{sup -} and SCN{sup -}, are shown to be transported by CLC-ec1, but with reduced H{sup +} counter-transport. The loss of proton coupling to these anions is accompanied by an absence of bound anions in the central and external Cl{sup -} binding sites in the protein's anion selectivity region, as revealed by crystallographic comparison of Br{sup -} and SeCN{sup -} bound to this region.

Authors:: Nguitragool, W; Miller, C

Publication Date:: Sun Jan 01 00:00:00 EST 2006

Research Org.:: Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source

Sponsoring Org.:: Doe - Office Of Science

OSTI Identifier:: 914359

Report Number(s):: BNL-78927-2007-JA
Journal ID: ISSN 0022-2836; JMOBAK; TRN: US0802856

DOE Contract Number:: DE-AC02-98CH10886

Resource Type:: Journal Article

Journal Name:: J. Mol. Biol.

Additional Journal Information:: Journal Volume: 362; Journal ID: ISSN 0022-2836

Country of Publication:: United States

Language:: English

Subject:: 59 BASIC BIOLOGICAL SCIENCES; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ANIONS; PROTEINS; PROTONS; REGULATIONS; STOICHIOMETRY; national synchrotron light source

Citation Formats


                    Nguitragool, W, and Miller, C. Uncoupling of a CLC Cl-/H+ exchange transporter by polyatomic anions.  United States: N. p., 2006. 
        Web.  doi:10.1016/j.jmb.2006.07.006.

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                    Nguitragool, W, & Miller, C. Uncoupling of a CLC Cl-/H+ exchange transporter by polyatomic anions.  United States.  https://doi.org/10.1016/j.jmb.2006.07.006

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                    Nguitragool, W, and Miller, C. 2006.  
        "Uncoupling of a CLC Cl-/H+ exchange transporter by polyatomic anions".  United States.  https://doi.org/10.1016/j.jmb.2006.07.006.

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@article{osti_914359,

  title        = {Uncoupling of a CLC Cl-/H+ exchange transporter by polyatomic anions},

  author       = {Nguitragool, W and Miller, C},

  abstractNote = {CLC-ec1 is a bacterial archetype of CLC transporters, a ubiquitous class of proteins that catalyze transmembrane exchange of Cl{sup -} and H{sup +} 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{sup -}/1 H{sup +}. In addition to Cl{sup -} and Br{sup -}, two non-halide ions, NO{sub 3}{sup -} and SCN{sup -}, are shown to be transported by CLC-ec1, but with reduced H{sup +} counter-transport. The loss of proton coupling to these anions is accompanied by an absence of bound anions in the central and external Cl{sup -} binding sites in the protein's anion selectivity region, as revealed by crystallographic comparison of Br{sup -} and SeCN{sup -} bound to this region.},

  doi          = {10.1016/j.jmb.2006.07.006},

  url          = {https://www.osti.gov/biblio/914359},
  journal      = {J. Mol. Biol.},

  issn         = {0022-2836},

  number       = ,

  volume       = 362,

  place        = {United States},

  year         = {Sun Jan 01 00:00:00 EST 2006},

  month        = {Sun Jan 01 00:00:00 EST 2006}

}

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