2014 - Species differences in bacterial NhaA Na+/H+ exchangers
SURFE²R-technology (custom-built system) publication in FEBS Letters (2014)
Călinescu O., Danner E., Böhm M., Hunte C., Fendler K..
FEBS Letters (2014) 588(17):3111-3116
- The H. pylori NhaA Na+/H+ exchanger was previously reported to be pH-insensitive.
- We investigate H. pylori NhaA by SSM-based electrophysiology.
- H. pylori NhaA shows a similar profile to E. coli NhaA with a small acidic pK shift.
- NhaA exchangers from enterobacteria can be explained by the same mechanism.
Bacteria have adapted their NhaA Na+/H+ exchangers responsible for salt homeostasis to their different habitats. We present an electrophysiological and kinetic analysis of NhaA from Helicobacter pylori and compare it to the previously investigated exchangers from Escherichia coli and Salmonella typhimurium. Properties of all three transporters are described by a simple model using a single binding site for H+ and Na+. We show that H. pylori NhaA only has a small acidic shift of its pH-dependent activity profile compared to the other transporters and discuss why a more drastic change in its pH activity profile is not physiologically required.