In vitro selection for sense codon suppression

RNA. 2003 Jul;9(7):780-6. doi: 10.1261/rna.5350303.

Abstract

The universal genetic code links the 20 naturally occurring amino acids to the 61 sense codons. Previously, the UAG amber stop codon (a nonsense codon) has been used as a blank in the code to insert natural and unnatural amino acids via nonsense suppression. We have developed a selection methodology to investigate whether the unnatural amino acid biocytin could be incorporated into an mRNA display library at sense codons. In these experiments we probed a single randomized NNN codon with a library of 16 orthogonal, biocytin-acylated tRNAs. In vitro selection for efficient incorporation of the unnatural amino acid resulted in templates containing the GUA codon at the randomized position. This sense suppression occurs via Watson-Crick pairing with similar efficiency to UAG-mediated nonsense suppression. These experiments suggest that sense codon suppression is a viable means to expand the chemical and functional diversity of the genetic code.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Codon / genetics*
  • DNA, Complementary / genetics
  • Genetic Code
  • Molecular Sequence Data
  • Oligodeoxyribonucleotides
  • Plasmids
  • RNA, Antisense / genetics*
  • RNA, Messenger / genetics
  • RNA, Transfer / genetics
  • Templates, Genetic

Substances

  • Codon
  • DNA, Complementary
  • Oligodeoxyribonucleotides
  • RNA, Antisense
  • RNA, Messenger
  • RNA, Transfer