Amino-acid sequence of the catalytic subunit of the (Na+ + K+)ATPase deduced from a complementary DNA.

We have isolated and characterized a complementary DNA for the catalytic subunit of the sheep kidney sodium/potassium-dependent ATPase. The 1,016-amino-acid protein seems to have eight transmembrane domains. The apparent ouabain binding site is located at the extracellular junction of two transmembrane domains and is linked to the phosphorylation site by a 60-amino-acid conserved sequence that may be a major channel for energy transduction.