a phosphate monoester + H2O = an alcohol + phosphate Binds 1 Fe cation per subunit. Binds 1 zinc ion per subunit. Homodimer; disulfide-linked. Expressed in roots, stems, leaves, flowers and siliques. By phosphate deprivation, mostly isoform 2. May be due to intron retention. Belongs to the metallophosphoesterase superfamily. Purple acid phosphatase family.