Patent ID: 8173392

Claim:
A method for producing in a translation system a protein on the surface of a bacterial cell wherein said protein comprises at least one unnatural amino acid, the method comprising: providing the translation system with at least one nucleic acid encoding said protein which nucleic acid comprises at least one selector codon, wherein the nucleic acid encodes at least one Omp-A protein or portion thereof; providing the translation system with an orthogonal tyrosyl derived tRNA (O-tRNA), wherein the O-tRNA functions in the translation system and wherein the O-tRNA recognizes the at least one selector codon; providing the translation system with an orthogonal aminoacyl tRNA synthetase (O-RS), wherein the O-RS is derived from a tyrosyl RS, wherein the O-RS preferentially aminoacylates the O-tRNA with the at least one unnatural amino acid in the translation system and wherein the O-RS is selected from the group consisting of: a polypeptide comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 35-66 and conservative variants thereof and a polypeptide encoded by a polynucleotide comprising a nucleic acid sequence selected from the group consisting of: SEQ ID NO: 4-34 and conservative variants thereof; and providing the translation system with the at least one unnatural amino acid wherein the unnatural amino acid is a tyrosine analogue or a phenylalanine analogue; wherein the Km of the O-RS for the unnatural amino acid is lower than for any naturally occurring amino acid and wherein the kcat of the O-RS for aminoacylation of the O-tRNA with the unnatural amino acid is higher than aminoacylation of the O-tRNA with any naturally occurring amino acid.