The invention relates generally to methods of producing a protein comprising a first unnatural amino acid (UAA) and a second, different UAA, and proteins comprising a first UAA and a second, different UAA.

The present invention relates to a mutated virus. Said virus can be an influenza virus of human or other animal origin. The present invention also relates to a method for preparing the mutated virus, the method comprising introducing UAG codons into positions upstream of the stop codons per se of one or more genes of a viral genome by reverse genetic techniques. The present invention further relates to uses of the mutated virus, for example, as a live attenuated vaccine, or in replication of controllable and safe virus models, and the like.

The present invention involves the ability to 1) use a virus assisted directed evolution platform to significantly improve the activity of engineered nonsense-suppressor tRNAs in mammalian cells, 2) provide mutants of archaeal pyrrolysyl and E. coli leucyl tRNAs that show remarkably improved Uaa incorporation efficiency in mammalian cells, and 3) use these tRNAs to express recombinant proteins in mammalian cells incorporating Uaas at significantly improved yields.

Provided herein are, inter alia, methods of forming chemically reactive amino acids and methods of using same.

The invention relates to archaeal pyrrolysyl tRNA synthetases lacking a nuclear localization signal and/or comprising a nuclear export signal. The invention also relates to polynucleotides encoding said pyrrolysyl tRNA synthetases, eukaryotic cells comprising said polynucleotide and tRNA acylated by the pyrrolysyl tRNA synthetase or a polynucleotide encoding such tRNA, methods utilizing said cells for preparing polypeptides comprising unnatural amino acid residues, and kits useful in said methods.

The invention relates to a method for incorporating an unnatural amino acid into a protein of interest in a eukaryotic cell, said method comprising the steps of: i) providing a eukaryotic cell expressing an orthogonal tRNA synthetase-t RNA pair, a nucleic acid sequence of interest encoding said protein of interest, and a mutant eRF1, said mutant eRF1 having amino acid sequence having at least 60% sequence identity to the human wild type eRF1 sequence of SEQ ID NO: 4, said nucleic acid sequence of interest comprising a codon recognised by the tRNA at the position for incorporation of an unnatural amino acid; ii) incubating the eukaryotic cell in the presence of an unnatural amino acid to be incorporated into a protein encoded by the nucleic acid sequence of interest, wherein said unnatural amino acid is a substrate for the orthogonal tRNA synthetase; and iii) incubating the eukaryotic cell to allow incorporation of said unnatural amino acid into the protein of interest via the orthogonal tRNA synthetase-t RNA pair. The invention also relates to uses, host cells, combinations and kits.

This invention relates to methods of producing a rare amino acid- or non-natural amino acid-containing protein in a cell free protein synthesis system and kits for use in and for accomplishing same. Specifically, the methods comprise the steps of expressing at least one orthogonal suppressor tRNA (o-tRNA)/aminoacyl-tRNA synthetase (aaRS) pair or derivatives thereof specific for incorporation of a rare amino acid- or non-natural amino acid in an E. coli organism; preparing a lysate of said E. coli organism expressing said orthogonal suppressor tRNA (o-tRNA)/aminoacyl-tRNA synthetase (aaRS) pair; and contacting said lysate with a template DNA containing a mutant gene in which at least one amino acid codon at a given site of the protein-encoding gene has been mutated into an amber or ochre mutation and further providing a cognate rare amino acid or non-natural amino acid and other factors necessary for protein synthesis; wherein protein synthesis occurs following said contact to produce a protein containing said at least one rare amino acid or said non-natural amino acid. Kits for use are described, as well.

The invention relates to archaeal pyrrolysyl tRNA synthetases lacking a nuclear localization signal and/or comprising a nuclear export signal. The invention also relates to polynucleotides encoding said pyrrolysyl tRNA synthetases, eukaryotic cells comprising said polynucleotide and tRNA acylated by the pyrrolysyl tRNA synthetase or a polynucleotide encoding such tRNA, methods utilizing said cells for preparing polypeptides comprising unnatural amino acid residues, and kits useful in said methods.

The disclosure provides amino acid sequence variants of orthogonal aminoacyl-tRNA synthetases (AARSs) having increased activity and selectivity compared to previous AARSs, and methods of producing the same.

The invention relates to a polypeptide comprising an amino acid having a bicyclo[6.1.0]non-4-yn-9-ylmethanol (BCN) group, particularly when said BCN group is present as: a residue of a lysine amino acid. The invention also relates to a method of producing a polypeptide comprising a BCN group, said method comprising genetically incorporating an amino acid comprising a BCN group into a polypeptide. The invention also relates to an amino acid comprising bicyclo[6.1.0]non-4-yn-9-ylmethanol (BCN), particularly and amino acid which is bicyclo[6.1.0]non-4-yn-9-ylmethanol (BCN) lysine. In addition the invention relates to a PylRS tRNA synthetase comprising the mutations Y271M, L274G and C313A.