Enhancing the Translational Capacity of E. coli by Resolving the Codon Bias

Zoltan Lipinszki, Viktor Vernyik, Nora Farago, Tobias Sari, Laszlo G. Puskas, Frederick R. Blattner, Gyorgy Posfai, Zsuzsanna Gyorfy

Research output: Contribution to journalArticle

2 Citations (Scopus)


Escherichia coli is a well-established and popular host for heterologous expression of proteins. The preference in the choice of synonymous codons (codon bias), however, might differ for the host and the original source of the recombinant protein, constituting a potential bottleneck in production. Codon choice affects the efficiency of translation by a complex and poorly understood mechanism. The availability of certain tRNA species is one of the factors that may curtail the capacity of translation. Here we provide a tRNA-overexpressing strategy that allows the resolution of the codon bias, and boosts the translational capacity of the popular host BL21(DE3) when rare codons are encountered. In the BL21(DE3)-derived strain, called SixPack, copies of the genes corresponding to the six least abundant tRNA species have been assembled in a synthetic fragment and inserted into a rRNA operon. This arrangement, while not interfering with the growth properties of the new strain, allows dynamic control of the transcription of the extra tRNA genes, providing significantly elevated levels of the rare tRNAs in the exponential growth phase. Results from expression assays of a panel of recombinant proteins of diverse origin and codon composition showed that the performance of SixPack surpassed that of the parental BL21(DE3) or a related strain equipped with a rare tRNA-expressing plasmid.

Original languageEnglish
Pages (from-to)2656-2664
Number of pages9
JournalACS Synthetic Biology
Issue number11
Publication statusPublished - Nov 16 2018



  • E. coli
  • efficient translation
  • genome editing
  • rare tRNA genes
  • recombinant protein production

ASJC Scopus subject areas

  • Biomedical Engineering
  • Biochemistry, Genetics and Molecular Biology (miscellaneous)

Cite this

Lipinszki, Z., Vernyik, V., Farago, N., Sari, T., Puskas, L. G., Blattner, F. R., Posfai, G., & Gyorfy, Z. (2018). Enhancing the Translational Capacity of E. coli by Resolving the Codon Bias. ACS Synthetic Biology, 7(11), 2656-2664. https://doi.org/10.1021/acssynbio.8b00332