Addition of a photocrosslinking amino acid to the genetic code of Escherichia coli

Benzophenones are among the most useful photocrosslinking agents in biology. We have evolved an orthogonal aminoacyl-tRNA synthetase/tRNA pair that makes possible the in vivo incorporation of p-benzoyl-l-phenylalanine into proteins in Escherichia coli in response to the amber codon, TAG. This unnatural amino acid was incorporated with high translational efficiency and fidelity into the dimeric protein glutathione S-transferase. Irradiation resulted in efficient crosslinking (>50%) of the protein subunits. This methodology may prove useful for discovering and defining protein interactions in vitro and in vivo.

• UD
  U.S. Department of Energy
• DR
  Damon Runyon Cancer Research Foundation
• NI
  National Institutes of Health

  Award: GM62159