The plasma membrane ATPase of plants and fungi is a hydrogen ion pump. The proton gradient it generates drives the active transport of nutrients by H(+)-symport. The resulting external acidification and/or internal alkinization may mediate growth responses. ATP + H(+)(in) + H2O = ADP + 2 H(+)(out) + phosphate In addition to transient phosphorylation of the active site Asp residue, this protein, but not the product of the pma1 locus, is phosphorylated efficiently in isolated plasma membrane. Belongs to the cation transport ATPase (P-type) (TC 3.A.3) family. Type IIIA subfamily.