A method for identifying putative peptides of a given function from among nucleotide or peptide sequences of unknown function comprising the steps of: (i) obtaining a polynucleotide or polypeptide database; (ii) screening the database for the presence of a combination of nucleotides or amino acids indicative of the peptide of given function; (ii) identifying the polynucleotide or polypeptide sequences which comprise the combination of nucleotides or amino acids indicative of the peptide of given function.