Dual UTR-A novel 5′ untranslated region design for synthetic biology applications

Abstract

Bacterial 50 untranslated regions of mRNA (UTR) involve in a complex regulation of gene expression; however, the exact sequence features contributing to gene regulation are not yet fully understood. In this study, we report the design of a novel 50 UTR, dual UTR, utilising the transcriptional and translational characteristics of 50 UTRs in a single expression cassette. The dual UTR consists of two 50 UTRs, each separately leading to either increase in transcription or translation of the reporter, that are separated by a spacer region, enabling de novo translation initiation. We rationally create dual UTRs with a wide range of expression profiles and demonstrate the functionality of the novel design concept in Escherichia coli and Pseudomonas putida using different promoter systems and coding sequences. Overall, we demonstrate the application potential of dual UTR design concept in various synthetic biology applications ranging from fine-tuning of gene expression to maximisation of protein production.