This magnesium-dependent enzyme catalyzes the hydrolysis of ATP coupled with the transport of calcium. Transports calcium ions from the cytosol into the sarcoplasmic/endoplasmic reticulum lumen. Contributes to calcium sequestration involved in muscular excitation/contraction (By similarity). ATP + Ca(2+)(in) + H2O = ADP + Ca(2+)(out) + H(+) + phosphate Causes an allergic reaction in human. Binds to IgE. Belongs to the cation transport ATPase (P-type) (TC 3.A.3) family. Type IIA subfamily.