Phylogenetic trees for β subunit of H+- and Na+-translocating ATPases from several species. F-type Na+ translocating β subunits, AB602793 (ApNaβ), cce_1512 (cceNaβ), SYNPCC7002_G0144 (7002Naβ), AM1_D0157 (AM1Naβ), and AF522463 (IlyNaβ). F-type H+ translocating β subunits, AB602795 (ApHβ), cce_1512 (cceHβ), SYNPCC7002_G0144 (7002Hβ), AM1_D0157 (AM1Hβ), and spinach β subunit (spiβ, NP_054943). An A-type β subunit of Methanosarcina mazei, MetanoB (NP_632803.1) and V-type β subunit of Enterococcus faecalis, EnteroB (NP_815220.1) are shown.