Display Settings:

Format

Send to:

Choose Destination
We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Biochim Biophys Acta. 2010 Jun-Jul;1797(6-7):817-31. doi: 10.1016/j.bbabio.2010.03.023. Epub 2010 Mar 31.

Mitochondrial carriers function as monomers.

Author information

  • 1The Medical Research Council, Mitochondrial Biology Unit, Hills Road, Cambridge, CB2 0XY, UK. ek@mrc-mbu.cam.ac.uk

Abstract

Mitochondrial carriers link biochemical pathways in the mitochondrial matrix and cytosol by transporting metabolites, inorganic ions, nucleotides and cofactors across the mitochondrial inner membrane. Uncoupling proteins that dissipate the proton electrochemical gradient also belong to this protein family. For almost 35 years the general consensus has been that mitochondrial carriers are dimeric in structure and function. This view was based on data from inhibitor binding studies, small-angle neutron scattering, electron microscopy, differential tagging/affinity chromatography, size-exclusion chromatography, analytical ultracentrifugation, native gel electrophoresis, cross-linking experiments, tandem-fusions, negative dominance studies and mutagenesis. However, the structural folds of the ADP/ATP carriers were found to be monomeric, lacking obvious dimerisation interfaces. Subsequently, the yeast ADP/ATP carrier was demonstrated to function as a monomer. Here, we revisit the data that have been published in support of a dimeric state of mitochondrial carriers. Our analysis shows that when critical factors are taken into account, the monomer is the only plausible functional form of mitochondrial carriers. We propose a transport model based on the monomer, in which access to a single substrate binding site is controlled by two flanking salt bridge networks, explaining uniport and strict exchange of substrates.

Copyright © 2010 Elsevier B.V. All rights reserved.

PMID:
20362544
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Write to the Help Desk