Species differences in bacterial NhaA Na+/H+ exchangers
Octavian Călinescu1, Eva Danner1, Marc Böhm2
1Department of Biophysical Chemistry, Max Planck Institute of Biophysics, Frankfurt am Main, Germany.
FEBS Letters
|July 15, 2014
Summary
Helicobacter pylori NhaA exchangers maintain salt homeostasis. Our study shows H. pylori NhaA has a minor pH activity shift, unlike related bacteria, suggesting it
Area of Science:
- Microbiology
- Molecular Biology
- Biophysics
Background:
- Bacteria utilize NhaA Na(+)/H(+) exchangers for crucial salt homeostasis.
- NhaA exchangers exhibit habitat-specific adaptations in different bacterial species.
Purpose of the Study:
- To electrophysiologically and kinetically analyze the NhaA exchanger from Helicobacter pylori.
- To compare H. pylori NhaA properties with those from Escherichia coli and Salmonella typhimurium.
- To investigate the physiological relevance of observed pH activity profile differences.
Main Methods:
- Electrophysiological analysis of NhaA transporter function.
- Kinetic characterization of NhaA activity.
- Comparative analysis of NhaA exchangers from different bacterial species.
Main Results:
- A simple model with a single binding site for H(+) and Na(+) describes the properties of all three transporters.
- H. pylori NhaA exhibits a small acidic shift in its pH-dependent activity profile compared to E. coli and S. typhimurium NhaA.
Conclusions:
- The observed pH activity profile of H. pylori NhaA is consistent with its physiological requirements.
- A drastic shift in pH activity is not necessary for H. pylori NhaA function in its native habitat.
Keywords:
Cation/proton antiportEscherichia coliHelicobacter pyloriNhaASalmonella typhimuriumSolid supported membraneMore Related Videos
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