FIG. 1.

Alignment of the protein sequences, percent similarity, and percent identity for S. cerevisiae K⁺/H⁺ KHA1, L. lactis Na⁺/H⁺ LLUPP, E. coli K⁺/H⁺ KEFC, and E. hirae Na⁺/H⁺ NAPA. Amino acid residues identical in all four proteins are indicated by asterisks, amino acid residues identical in two or three proteins are indicated in bold, and putative transmembrane domains are indicated by an overline. Solid boxes indicate percent identity, and shaded boxes indicate percent similarity.