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Abstract In this comprehensive review, I focus on the twentyE. coliaminoacyl‐tRNA synthetases and their ability to charge non‐canonical amino acids (ncAAs) onto tRNAs. The promiscuity of these enzymes has been harnessed for diverse applications including understanding and engineering of protein function, creation of organisms with an expanded genetic code, and the synthesis of diverse peptide libraries for drug discovery. The review catalogues the structures of all known ncAA substrates for each of the 20E. coliaminoacyl‐tRNA synthetases, including ncAA substrates for engineered versions of these enzymes. Drawing from the structures in the list, I highlight trends and novel opportunities for further exploitation of these ncAAs in the engineering of protein function, synthetic biology, and in drug discovery.
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Initiation of Protein Synthesis with Non‐Canonical Amino Acids In Vivo
Abstract By transplanting identity elements into E. coli tRNAfMet, we have engineered an orthogonal initiator tRNA (itRNATy2) that is a substrate for Methanocaldococcus jannaschii TyrRS. We demonstrate that itRNATy2can initiate translation in vivo with aromatic non‐canonical amino acids (ncAAs) bearing diverse sidechains. Although the initial system suffered from low yields, deleting redundant copies of tRNAfMetfrom the genome afforded an E. coli strain in which the efficiency of non‐canonical initiation equals elongation. With this improved system we produced a protein containing two distinct ncAAs at the first and second positions, an initial step towards producing completely unnatural polypeptides in vivo. This work provides a valuable tool to synthetic biology and demonstrates remarkable versatility of the E. coli translational machinery for initiation with ncAAs in vivo.
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- Award ID(s):
- 1740549
- PAR ID:
- 10131412
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 59
- Issue:
- 8
- ISSN:
- 1433-7851
- Page Range / eLocation ID:
- p. 3122-3126
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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