The present invention relates to isolated polypeptides having phytase activity, recombinant DNA sequences encoding such polypeptides, methods of producing such polypeptides, and the use of the polypeptides in transgenic plants. The invention discloses polypeptides having affinity for the substrate phytate (1, 2, 3, 4, 5, 6 myo-inositol-hexakisphosphate, phytic acid), comprising an amino acid sequence as described by the invention. Furthermore, the invention discloses DNA fragments encoding the polypeptides, and cDNA fragments encoding the polypeptides. The polypeptides of the invention may, for example, be used as an additive in animal feeds, an additive in food for human consumption, or to extract proteins from rice bran. The invention also concerns a transgenic plant or part thereof, wherein the plant or part thereof has been genetically modified to comprise a polypeptide as defined by the invention.