Enzyme, EC 126.96.36.199; an ATP-powered ion pump that transports Ca2+ across the membrane against a large (up to 15,000-fold) concentration gradient. A representative member of the P-type ATPase family, which is in turn a member of the haloacid dehalogenase superfamily (Burroughs et al. 2006). EC 188.8.131.52 includes sarco(endo)plasmic reticulum calcium ATPase, commonly abbreviated as SERCA, and plasma membrane Ca2+-ATPase, abbreviated as PMCA. As SERCA transports 2 Ca2+ ions per ATP hydrolyzed from the cytoplasm into the lumen of sarcoplasmic reticulum and 2 or 3 H+ in the opposite direction, it may be termed “Ca2+, H+-ATPase,” similarly to Na+, K+-ATPase. PMCA transports one Ca2+ per ATP.
Biological Function and Amino Acid Sequence Information