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Pyrrolysyl-tRNA synthetase: An ordinary enzyme but an outstanding genetic code expansion tool
- Wan, Wei, Tharp, Jeffery M., Liu, Wenshe R.
- BBA - Proteins and Proteomics 2014 v.1844 pp. 1059-1070
- acids, amino acids, aminoacyl tRNA ligases, genetic code, proteins, stop codon
- The genetic incorporation of the 22nd proteinogenic amino acid, pyrrolysine (Pyl) at amber codon is achieved by the action of pyrrolysyl-tRNA synthetase (PylRS) together with its cognate tRNAPyl. Unlike most aminoacyl-tRNA synthetases, PylRS displays high substrate side chain promiscuity, low selectivity toward its substrate α-amine, and low selectivity toward the anticodon of tRNAPyl. These unique but ordinary features of PylRS as an aminoacyl-tRNA synthetase allow the Pyl incorporation machinery to be easily engineered for the genetic incorporation of more than 100 non-canonical amino acids (NCAAs) or α-hydroxy acids into proteins at amber codon and the reassignment of other codons such as ochre UAA, opal UGA, and four-base AGGA codons to code NCAAs.