P-type ATPases, such as ATP11B, are phosphorylated in their intermediate state and drive uphill transport of ions across membranes. Several subfamilies of P-type ATPases have been identified. One subfamily transports heavy metal ions, such as Cu(2+) or Cd(2+). Another subfamily transports non-heavy metal ions, such as H(+), Na(+), K(+), or Ca(+). A third subfamily transports amphipaths, such as phosphatidylserine.
^Nagase T, Ishikawa K, Suyama M, Kikuno R, Hirosawa M, Miyajima N et al. (Feb 1999). "Prediction of the coding sequences of unidentified human genes. XIII. The complete sequences of 100 new cDNA clones from brain which code for large proteins in vitro". DNA Research6 (1): 63–70. doi:10.1093/dnares/6.1.63. PMID10231032.
^Halleck MS, Lawler JF JR, Blackshaw S, Gao L, Nagarajan P, Hacker C et al. (Nov 1999). "Differential expression of putative transbilayer amphipath transporters". Physiological Genomics1 (3): 139–50. PMID11015572.