Catalytic component of a P4-ATPase flippase complex which catalyzes the hydrolysis of ATP coupled to the transport of aminophospholipids, phosphatidylserines (PS) and phosphatidylethanolamines (PE), from the outer to the inner leaflet of intracellular membranes (PubMed:30018401). May contribute to the maintenance of membrane lipid asymmetry in endosome compartment (PubMed:30018401). ATP + H2O + phospholipidSide 1 = ADP + phosphate + phospholipidSide 2. a 1,2-diacyl-sn-glycero-3-phospho-L-serine(out) + ATP + H2O = a 1,2-diacyl-sn-glycero-3-phospho-L-serine(in) + ADP + H(+) + phosphate a 1,2-diacyl-sn-glycero-3-phosphoethanolamine(out) + ATP + H2O = a 1,2-diacyl-sn-glycero-3-phosphoethanolamine(in) + ADP + H(+) + phosphate The ATPase activity is up-regulated by aminophospholipids PS and PE. Component of a P4-ATPase flippase complex which consists of a catalytic alpha subunit ATP11B and an accessory beta subunit TMEM30A. Exit from the endoplasmic reticulum requires the presence of TMEM30A, but not TMEM30B (PubMed:21914794). In the presence of TMEM30A, mainly located in recycling endosomes (PubMed:21914794). Belongs to the cation transport ATPase (P-type) (TC 3.A.3) family. Type IV subfamily. Intron retention.