Patent ID: 7270969

Claim:
A method of constructing an expression library for expressing a peptide having a conformation sufficient for binding to a target protein or nucleic acid, said method comprising: (a) producing nucleic acid fragments from nucleic acids derived from two or more microorganisms or eukaryotes containing compact genomes, each of said microorganisms or eukaryotes having a substantially sequenced genome; and (b) selecting nucleic acid fragments of sufficient length to encode a peptide comprising a protein domain having an average length of at least 12 to 15 amino acids; and (c) inserting the nucleic acid fragments at (b) into a suitable expression construct in an amount proportional to the size of the genome from which the fragments were derived thereby producing recombinant constructs, wherein each fragment is in operable connection with a promoter sequence that is capable of conferring expression of that fragment.