Catalyzes the hydrolysis of ATP coupled with the transport of calcium. The transport is electrogenic with a probable ATP:Ca(2+):H(+) stoichiometry of 1:1:1. May have an important role in survival of the bacterium when stressed by a combination of a high calcium concentration and alkaline pH. ATP + Ca(2+)(in) + H2O = ADP + Ca(2+)(out) + H(+) + phosphate Phosphorylation is inhibited by EGTA and vanadate. ATPase activity is stimulated by Sr(2+). Inhibited by very high concentrations of cyclopiazonic acid (CPA). Optimum pH is 9.0. Belongs to the cation transport ATPase (P-type) (TC 3.A.3) family. Type IIA subfamily.