An archaebacteria-derived glutamyl-tRNA synthetase and tRNA pair for unnatural amino acid mutagenesis of proteins in Escherichia coli

Area of Science:

• Synthetic biology
• Protein engineering
• Molecular biology

Background:

• Orthogonal aminoacyl-tRNA synthetase and tRNA pairs enable the genetic incorporation of unnatural amino acids into proteins.
• Previous systems in Escherichia coli primarily utilized tyrosine orthogonal pairs.
• Expanding the repertoire of available orthogonal pairs is crucial for increasing protein diversity.

Purpose of the Study:

• To develop a novel orthogonal glutamic acid synthetase and tRNA pair for use in Escherichia coli.
• To assess the efficiency of this new pair in suppressing amber nonsense codons.
• To broaden the scope of unnatural amino acids that can be genetically incorporated into proteins.

Main Methods:

• Designed an orthogonal tRNA(Glu) based on archaeal consensus sequences.
• Utilized a glutamyl-tRNA synthetase from Pyrococcus horikoshii.
• Tested the amber nonsense codon suppression efficiency of the developed pair in E. coli.

Main Results:

• Successfully generated an orthogonal glutamic acid synthetase and tRNA pair.
• The new pair demonstrated amber nonsense codon suppression efficiency comparable to existing orthogonal tyrosine pairs.
• This system facilitates the incorporation of unnatural amino acids into polypeptides.

Conclusions:

• The development of an orthogonal glutamic acid pair significantly expands the diversity of unnatural amino acid structures that can be incorporated into proteins.
• This advancement provides a new tool for protein engineering and synthetic biology applications.
• The findings pave the way for creating novel proteins with tailored functionalities.