InterPro domain: IPR041792

Purple acid phosphatases (PAPs) belong to a diverse family of binuclear metallohydrolases that have been identified and characterized in plants, animals, and fungi. PAPs contain a binuclear metal centre and their characteristic pink or purple color derives from a charge-transfer transition between a tyrosine residue and a chromophoric ferric ion within the binuclear centre. PAPs catalyze the hydrolysis of a wide range of activated phosphoric acid mono- and di-esters and anhydrides. PAPs are distinguished from the other phosphatases by their insensitivity to L-(+) tartrate inhibition and are therefore also known as tartrate resistant acid phosphatases (TRAPs). While only a few copies of PAP-like genes are present in mammalian and fungal genomes, multiple copies are present in plant genomes [ 1 , 2 ]. PAPs belong to the metallophosphatase (MPP) superfamily.

1. Purple acid phosphatases from bacteria: similarities to mammalian and plant enzymes. Gene 255, 419-24
2. Molecular and biochemical characterization of AtPAP15, a purple acid phosphatase with phytase activity, in Arabidopsis. Plant Physiol. 151, 199-209