Novel thermostable phytase with 2.1Åcrystal structure

摘要

The present invention relates to a thermostable enzyme with a 2.1 crystal structure of a propeller type comprising six external blades that encompass the outer boundary of the crystal and six internal calcium-binding sites that are embedded inside the above crystal. Each of the six blades comprises 4 or 5 anti-parallel beta-strands, and the six calcium binding sites consist of 3 high-affinity calcium binding sites and 3 low-affinity binding sites, which are involved in the enzyme's thermostability and catalytic activity, respectively. The above-mentioned Ca2+ binding motifs are expected to be utilized in synthesizing highly thermostable proteins and the elucidation of active sites of an enzyme from a three-dimensional structure can help to design new enzymes having those sites with the aid of recent advanced technology of protein engineering