AN ACID-PHOSPHATASE FROM ASPERGILLUS-FICUUM HAS HOMOLOGY TO PENICILLIUM-CHRYSOGENUM PHOA

Three secreted acid phosphatases had previously been characterized fro m Aspergillus ficuum grown under conditions of limited phosphate. One of these could not be readily separated from AFPhyB, a pH 2.5 optimum acid phosphatase with phytase activity. From extensive protein sequenc e analysis and subsequent cloning of the gene, we have shown that the AFPhyB protein fraction contains a fourth secreted acid phosphatase (A FPhoA) that has 64% homology to a phosphate-repressible acid phosphata se from Penicillium chrysogenum, Garnier plot analysis revealed that t he putative phosphate catalytic domain of AFPhoA at His(215)Asp(216) i s similar to those of other acid phosphatases, but that AFPhoA lacks t he phosphate-binding motif RHGXRXP of known histidine phosphatases. (C ) 1944 Academic Press, Inc.