Transcriptional termination at a fully rho-independent site in Escherichia coli is prevented by uninterrupted translation of the nascent RNA.

Abstract

We have examined the possibility that translation reading through a fully rho‐independent transcriptional terminator in Escherichia coli might prevent termination, as already established for rho‐dependent terminators. Plasmids were constructed with and without interposition of the rho‐independent coliphage T7 ‘early’ terminator between a promoter and galK. Our constructions ensured either that there was no upstream translation, or that translation (initiated at the galE ribosome binding site) stopped upstream of, or at the normal position (the T7 gene 1.3 stop codon) with respect to, the transcriptional terminator; or else downstream of both this stop codon and the terminator. Our galactokinase enzyme and mRNA measurements on strains harbouring these plasmids indicate that ‘readthrough translation’ eliminates transcriptional termination at the T7 site. This effect is suppressed if the rate of ribosome movement is reduced with fusidic acid.

Bunyavirus mRNA synthesis is coupled to translation to prevent premature transcription termination

“…The results show that translocation abrogates transcription termination, thus confirming the central tenet of the model. Consequently, these results support the proposed role of RNA interactions in the termination mechanism, as the ability of ribosomes to disrupt RNA structures is well documented (Wright and Hayward 1987).…”

Transcription termination in the Escherichia coli dnaA gene is not mediated by the internal DnaA box

“…1). Results from several laboratories (2,22,27,38,39) support the proposal of Stanssens et al (33) that transcriptional polarity does not require complete arrest of translation, as is the case with the polarity caused by nonsense mutations (26). Increased spacing between the RNA polymerase and the leading ribosome would seem to satisfy the requirements for intracistronic termination to occur.…”

Molecular Cloning and High-Level Expression of Human Polymerase β cDNA and Comparison of the Purified Recombinant Human and Rat Enzymes

“…The vectors employed for human ␤-pol expression were designed to maximize the probability of efficient translation initiation of the ␤-pol mRNA. It has been shown that efficient translation of an mRNA can protect it from degradation (36) and prevents or greatly reduces rho-dependent and rho-independent transcription termination (37,38). Since initiation is usually the rate-limiting step in translation (39), it follows that it is appropriate to focusing on maximizing translation initiation efficiency of mRNAs targeted for overproduction in E. coli.…”