Patent ID: 8227209

Claim:
A process for producing a functional non-naturally occurring protein having a specific amino acid type(s) replaced with a natural amino acid(s) other than the specific amino acid type(s), the process comprising: a) matching a nucleic acid portion having a nucleotide sequence reflecting the genotype with a protein portion that is a product translated from the nucleic acid portion in a cell-free protein synthesis system comprising (i) a suppressor tRNA(s) corresponding to codon(s) for the specific amino acid type(s) to be replaced, thereby inserting into a synthesized protein another amino acid instead of the specific amino acid type(s) to be replaced; (ii) natural amino acids other than the specific amino acid type(s), and (iii) optionally an inhibitor(s) specific for an aminoacyl-tRNA synthetase(s) for the specific amino acid type(s), to obtain a matched molecule containing the nucleic acid portion and the protein portion; b) selecting the matched molecule obtained in step a), and if the matched molecule is determined to have a selected activity, then performing step e); otherwise, performing next step c); c) introducing a mutation into the nucleic acid portion of the matched molecule obtained in step b); d) amplifying the nucleic acid portion obtained in step c), and repeating steps a)-c) utilizing the nucleic acid portion of step d); and e) obtaining a functional non-naturally occurring protein having the same amino acid sequence of the protein portion of the matched molecule obtained in step b), by using a protein synthesis system containing naturally occurring amino acids.