Complex Formation by the mrpABCDEFG Gene Products, Which Constitute a Principal Na+/H+ Antiporter in Bacillus subtilis

The Bacillus subtilis Mrp (also referred to as Sha) is a particularly unusual Na+/H+ antiporter encoded by mrpABCDEFG. Using His tagging of Mrp proteins, we showed complex formation by the mrpABCDEFG gene products by pull-down and blue native polyacrylamide gel electrophoresis analyses. This is the first molecular evidence that the Mrp is a multicomponent antiporter in the cation-proton antiporter 3 family.