Abstract
Engineering of orthogonal systems functional across diverse hosts can benefit from employing universal regulatory DNA elements. Here, we screened a number of composite promoters in plant, fungal, and bacterial hosts, identifying variants that drive strong constitutive expression in Nicotiana tabacum, Saccharomyces cerevisiae, Escherichia coli, and Agrobacterium tumefaciens, or only in the eukaryotic subset of these organisms. These promoters can be used in universal vectors to co-optimize for different hosts in directed evolution, engineering of biosynthetic pathways, or other biotechnological tasks that require host switching.