XVI International Botanical Congess

Multiple inositol polyphosphate phosphatase (MIPP) is capable of hydrolyzing phytic acid, but its primary role is in controlling the signaling activities of higher inositol polyphosphates in animal cells. Both A.niger phytase and MIPP contain the amino acid sequence RHGXRXP unique to the histidine acid phosphatase class of enzymes. A sequence analysis of phytase and mammalian MIPP revealed the conservation of several other regions in addition to the active site in these enzymes. Utilizing an available molecular model of phytase, based on X-ray crystallographic data, the position of these conserved regions was correlated to specific structure features of this molecule. This research is directed to the identification of homologous structures necessary for enzyme function.