IDENTIFICATION OF A HISTIDINE ACID-PHOSPHATASE (PHYA)-LIKE GENE IN ARABIDOPSIS-THALIANA

A close examination of the protein sequence encoded by the Arabidopsis thaliana gene F21M12.26 reveals the gene product to be a phosphomonoe sterase, acid optimum (EC 3.1.3.2). A subclass of this broad acid phos phatase is also known as 'histidine acid phosphatase.' This is the fir st sequence-based evidence for a 'histidine acid phosphatase' in a dic otyledon. One important member of this class of enzymes is Aspergillus niger (ficuum) phytase, which came into prominence for its commercial application as a feed additive. The putative protein from A. thaliana gene F21M12.26 shares many important features of Aspergillus phytase, namely, size, active-site sequence, catalytic dipeptide and ten cyste ine residues located in the key areas of the molecule, but lacks all n ine N-glycosylation sites. (C) 1998 Academic Press.