2018 Articles
Structure-based analysis of CysZ-mediated cellular uptake of sulfate
Sulfur, most abundantly found in the environment as sulfate (SO42-), is an essential element in metabolites required by all living cells, including amino acids, co-factors and vitamins. However, current understanding of the cellular delivery of SO42- at the molecular level is limited. CysZ has been described as a SO42- permease, but its sequence family is without known structural precedent. Based on crystallographic structure information, SO42- binding and flux experiments, we provide insight into the molecular mechanism of CysZ-mediated translocation of SO42- across membranes. CysZ structures from three different bacterial species display a hitherto unknown fold and have subunits organized with inverted transmembrane topology. CysZ from Pseudomonas denitrificans assembles as a trimer of antiparallel dimers and the CysZ structures from two other species recapitulate dimers from this assembly. Mutational studies highlight the functional relevance of conserved CysZ residues.
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Also Published In
- Title
- eLife
- DOI
- https://doi.org/10.7554/eLife.27829
More About This Work
- Academic Units
- Physiology and Cellular Biophysics
- Biochemistry and Molecular Biophysics
- Psychiatry
- Published Here
- November 27, 2018