摘要 |
FIELD: chemistry. ^ SUBSTANCE: present invention relates to biotechnology. The invention discloses a composition for coexpression in an eubacterial host cell orthogonal tRNA (O-tRNA) and orthogonal aminoacyl-tRNA synthetase (O-RS), which preferably aminoacylates said O-tRNA with an unnatural amino acid. The disclosed composition consists of two nucleic acid constructs: the first construct contains promoter and terminator nucleotide sequences derived from an E.coli proline tRNA gene and which is derived from the archaea of the expressed sequence, which encodes one O-tRNA or is a polycistronic operon, and the second construct contains a modified E.coli glnS promoter and the expressed nucleotide sequence which encodes the corresponding O-RS. Described is a translation system which includes the disclosed vector constructs, and a method of obtaining the polypeptide of interest which contains an unnatural amino acid in a genetically defined position. ^ EFFECT: obtaining properties with new properties, which are defined by inclusion of unnatural amino acids into a predetermined position. ^ 54 cl, 8 dwg, 7 ex |