. "The Enterococcus hirae ATPase CopA is a member of the recently discovered heavy metal ATPases and shares 43% sequence identity with the human Menkes and Wilson copper ATPases. To study CopA biochemically, it was overexpressed in E. coli with an N-terminal histidine tag and purified to homogeneity by nickel affinity chromatography. The purified CopA catalyzed ATP hydrolysis with a V(max) of 0.15 micromol/min/mg and a K(m) for ATP of 0.2 mM and had an optimum pH of 6.25. The activity was 3-to 4-fold stimulated by reconstitution into proteoliposomes. The enzyme formed an acylphosphate intermediate. Its kinetics of formation and the effects of inhibitors and metal ions upon it support a function of CopA in copper transport. Purification and functional reconstitution of CopA provides the basis to study copper transport in vitro." . . "Biochem. Biophys. Res. Commun." . "Solioz M." . "Wunderli-Ye H." . "2001"^^ . "713-719" . "Purification and functional analysis of the copper ATPase CopA of Enterococcus hirae." . "280" . "doi:10.1006/bbrc.2000.4176" .