Current Progresses in Phytase Research: Three-Dimensional Structure and Protein Engineering

Abstract

Phytase is one of the most important feed additive enzymes for monogastric animal, because it hydrolyzes the indigestible phytate in the cereal-based feedstock to release phosphate as an essential nutrient. To understand its molecular machinery, the three-dimensional structures of various types of phytases and complexes have been studied extensively. For commercial applications, important properties such as higher catalytic efficiency and higher thermostability are desired. Since a phytase with both beneficial characteristics is hardly found in nature, various protein engineering strategies are popular in modifying the existing enzymes with enhanced performance. In this review, the up-to-date status of phytase structural and engineering studies is summarized. In addition, structural perspectives of some engineered phytases with improved properties are also provided. These results broaden the understanding of phytases and will be important for phytase applications in the future.