Mechanism of Na+/H+ antiporting

Desalination of E. Coli. in Homeric hymn

Heed, the readers of Science,
Secret ways of the antiporter.
This family of membrane proteins,
Trading one sodium inside cell, with
Two protons outside,
So all life is alive, in acid and brine.
Its structure recently unveiled,
Using extraction from E. Coli.;
Yet its method of act,
Hitherto uncomprehended.
This method we tell, by a host of
Molecular simulations;
By thinking and rethinking of
Clues already seen in labs:

Three membranous aspartates,
Protonating and deprotonating,
Move the protein in action.
Asp a hundred sixty four,
Deprotonating and protonating,
Binds and releases sodium ions;
Asp a hundred sixty three,
Protonating and deprotonating,
Opens the gate to peri- and cyto- plasm.
Asp a hundred and thirty three,
Be the pKa high, be its charge negative,
Keeps the antiporting in flux.
To ascertain our theory,
We return to the bench,
Modifying the protein by
Mutagenesis.
Happily the outcome,
With our predictions agreed.