This model describes proton pyrophosphatases from eukaryotes (predominantly plants), archaea and bacteria. It is an integral membrane protein and is suggested to have about 15 membrane spanning domains. Proton translocating inorganic pyrophosphatase, like H(+)-ATPase, acidifies the vacuoles and is pivotal to the vacuolar secondary active transport systems in plants. [Transport and binding proteins, Cations and iron carrying compounds]
Jiyao W et al.(2023). "The conserved domain database in 2023.",