Description | This entry includes purple acid phosphatases ( ), which are metal dependent, binding two metal ions. Metal binding ligands and residues involved in resistance to tartrate inhibition are conserved [ ].Purple acid phosphatase 3, 4, 7, 8 and 17 are found in plants, bind zinc and iron, and the genes are predominantly transcribed in flowers [ ]. Purple acid phosphatase 17 (PAP17) is induced in response to phosphate starvation, a condition occurring in phosphate-poor soils, and the plant hormone abscisic acid (ABA) and salt stress. Like mammalian acid phosphatase 5, PAP17 has peroxidation activity [].THis entry also includes Glideosome-associated protein 50 (GAP50) from Plasmodium falciparum, a component of the glideosome complex involved in parasite gliding motility and host cell invasion [ ]. Its structures has an overall similarity to purple acid phosphatases. However, it has little homology regarding the nature of the residues in the active site region purple acid phosphatases. While the latter contain a phosphate bridged binuclear Fe-site coordinated by seven side chains with the Fe-ions 3.2 A apart, GAP50 in the crystals has two cobalt ions each with one protein ligand and a distance between the Co2 ions of 18 A []. The phosphatase activity of GAP50 is controversial [].Acid phosphatase 5 (ACP5) removes the mannose 6-phosphate recognition marker from lysosomal proteins. The exact site of dephosphorylation is not clear. Evidence suggests dephosphorylation may take place in a prelysosomal compartment as well as in the lysosome [ ]. ACP5 belongs to the metallophosphatase (MPP) superfamily. MPPs are functionally diverse, but all share a conserved domain with an active site consisting of two metal ions (usually manganese, iron, or zinc) co-ordinated with octahedral geometry by a cage of histidine, aspartate, and asparagine residues []. | Name | Purple acid phosphatase |
Short Name | Acid_PPase | Type | Family |