No abstract

Ligand-dependent control of gene expression is essential for gene functional analysis, target validation, protein production, and metabolic engineering. However, the expression tools currently available are difficult to transfer between species and exhibit limited mechanistic diversity. Here we demonstrate how the modular architecture of purine riboswitches can be exploited to develop orthogonal and chimeric switches that are transferable across diverse bacterial species, modulating either transcription or translation, to provide tunable activation or repression of target gene expression, in response to synthetic non-natural effector molecules. Our novel riboswitch-ligand pairings are shown to regulate physiologically important genes required for bacterial motility in Escherichia coli and cell morphology in Bacillus subtilis. These findings are relevant for future gene function studies and antimicrobial target validation, while providing new modular and orthogonal regulatory components for deployment in synthetic biology regimes.

Re-engineered riboswitches that no longer respond to cellular metabolites, but that instead can be controlled by synthetic molecules, are potentially useful gene regulatory tools for use in synthetic biology and biotechnology fields. Previously, extensive genetic selection and screening approaches were employed to re-engineer a natural adenine riboswitch to create orthogonal ON-switches, enabling translational control of target gene expression in response to synthetic ligands. Here, we describe how a rational targeted approach was used to re-engineer the PreQ1 riboswitch from Bacillus subtilis into an orthogonal OFF-switch. In this case, the evaluation of just six synthetic compounds with seven riboswitch mutants led to the identification of an orthogonal riboswitch-ligand pairing that effectively repressed the transcription of selected genes in B. subtilis. The streamlining of the re-engineering approach, and its extension to a second class of riboswitches, provides a methodological platform for the creation of new orthogonal regulatory components for biotechnological applications including gene functional analysis and antimicrobial target validation and screening.

PurposeThe purpose of this paper is to develop a framework to link founding team and start‐up competitive advantage in the context of the Taiwanese technology‐based ventures.Design/methodology/approachThe paper analyzes 211 start‐ups of the technology‐based sector and verifies the relationship between entrepreneur resources, trust, founding team partners' commitments, and start‐up competitive advantage.FindingsIn technology‐based start‐ups, the competitive advantage of a start‐up is determined by the founding team partners' commitments and the resources an entrepreneur has.Research limitations/implicationsThis study is retrospective which relies on technology‐based founding team members as the primary research subjects, some respondents may observe the performance of their start‐ups today and then make attributions about the past to explain that performance.Practical implicationsUtilizations of personal networks are important in the early stage of technology‐based start‐ups; through networking and using trust, an entrepreneur can gain the critical resources and competitive advantage required in the development of a business.Originality/valueIn technology‐based start‐ups, trust, not the resources an entrepreneur has, is an effective way by which entrepreneurs can win founding team partners' commitments.

No abstract