The potassium-transporting ATPase heterodimer comprising of catalytic alpha and stabilising beta chains (ATP12A:ATP4B), catalyzes the hydrolysis of ATP coupled with the exchange of H+ and K+ ions across the plasma membrane. The human gene ATP12A encodes the catalytic alpha subunit (Grishin et al. 1994). One human gene encodes the beta subunit, ATP4B (Ma et al. 1991). ATP12A is responsible for potassium absorption in various tissues.
P-type potassium:proton transporter activity of ATP12A:ATP4B [plasma membrane]