RT Journal Article
SR Electronic
T1 Tuning of recombinant protein expression in Escherichia coli by manipulating transcription, translation initiation rates and incorporation of non-canonical amino acids
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 100982
DO 10.1101/100982
A1 Orr Schlesinger
A1 Yonatan Chemla
A1 Mathias Heltberg
A1 Eden Ozer
A1 Ryan Marshall
A1 Vincent Noireaux
A1 Mogens Høgh Jensen
A1 Lital Alfonta
YR 2017
UL http://biorxiv.org/content/early/2017/01/22/100982.abstract
AB Protein synthesis in cells has been thoroughly investigated and characterized over the past 60 years. However, some fundamental issues remain unresolved, including the reasons for genetic code redundancy and codon bias. In this study, we changed the kinetics of the E. coli transcription and translation processes by mutating the promoter and ribosome binding domains and by using genetic code expansion. The results expose a counterintuitive phenomenon, whereby an increase in the initiation rates of transcription and translation lead to a decrease in protein expression. This effect can be rescued by introducing slow translating codons into the beginning of the gene, by shortening gene length or by reducing initiation rates. Based on the results, we developed a biophysical model, which suggests that the density of co-transcriptional translation plays a role in bacterial protein synthesis. These findings indicate how cells use codon bias to tune translation speed and protein synthesis.