Patent ID: 8114654

Claim:
A composition comprising an orthogonal aminoacyl-tRNA synthetase (O-RS) wherein the ORS preferentially aminoacylates an O-tRNA with a meta-substituted tyrosine unnatural amino acid, wherein the O-RS comprises an amino acid sequence with at least 90% identity to SEQ ID NO: 1, wherein the O-RS further comprises a Leu amino acid in a position of the O-RS corresponding to Tyr32 of SEQ ID NO: 4, a Ser amino acid residue in a position of the O-RS corresponding to Ala67 of SEQ ID NO: 4, an Asn amino acid residue in a position of the O-RS corresponding to His70 of SEQ ID NO: 4 and a Gln residue in a position of the O-RS corresponding to Ala167 of SEQ ID NO: 4; and SEQ ID NO: 4 is the wild type sequence.