The present application provides a method for predicting the functional
site of a protein using data of the entire proteins of an organism of
which genome data or cDNA data is known. More specifically, the present
application provides a method for predicting a protein functional site,
comprising the steps of calculating the frequency of occurrence of an
oligopeptide in the entire proteins, calculating the value of each
amino-acid residue contributing to the frequency of occurrence as the
representative value of the function, and predicting the protein
functional site by using the representative value of function as an
indicator. The present also provides a system for predicting a functional
site for automatically performing said methods. Additionally, the present
application provides a method for preparing a function-modified protein
comprising subjecting the amino-acid residues composing the functional
site identified by the method described above to artificial mutation, and
a novel thermophilic DNA polymerase prepared by the method.