In synthetic biology,microbial chassis including yeast Saccharomyces cerevisiae are iteratively engineered with increasing complexity and scale.Wet-lab genetic engineering tools are developed and optimised to facilita...In synthetic biology,microbial chassis including yeast Saccharomyces cerevisiae are iteratively engineered with increasing complexity and scale.Wet-lab genetic engineering tools are developed and optimised to facilitate strain construction but are often incompatible with each other due to shared regulatory elements,such as the galactose-inducible(GAL)promoter in S.cerevisiae.Here,we prototyped the cyanamide-induced ^(I−)SceI expression,which triggered double-strand DNA breaks(DSBs)for selectable marker removal.We further combined cyanamide-induced ^(I−)SceI-mediated DSB and maltose-induced MazF-mediated negative selection for plasmid-free in situ promoter substitution,which simplified the molecular cloning procedure for promoter characterisation.We then characterised three tetracycline-inducible promoters showing differential strength,a non-leakyβ-estradiol-inducible promoter,cyanamide-inducible DDI2 promoter,bidirectional MAL32/MAL31 promoters,and five pairs of bidirectional GAL1/GAL10 promoters.Overall,alternative regulatory controls for genome engineering tools can be developed to facilitate genomic engineering for synthetic biology and metabolic engineering applications.展开更多
基金supported by the Australian Government through the Australian Research Council Centres of Excellence funding scheme(project CE200100029).
文摘In synthetic biology,microbial chassis including yeast Saccharomyces cerevisiae are iteratively engineered with increasing complexity and scale.Wet-lab genetic engineering tools are developed and optimised to facilitate strain construction but are often incompatible with each other due to shared regulatory elements,such as the galactose-inducible(GAL)promoter in S.cerevisiae.Here,we prototyped the cyanamide-induced ^(I−)SceI expression,which triggered double-strand DNA breaks(DSBs)for selectable marker removal.We further combined cyanamide-induced ^(I−)SceI-mediated DSB and maltose-induced MazF-mediated negative selection for plasmid-free in situ promoter substitution,which simplified the molecular cloning procedure for promoter characterisation.We then characterised three tetracycline-inducible promoters showing differential strength,a non-leakyβ-estradiol-inducible promoter,cyanamide-inducible DDI2 promoter,bidirectional MAL32/MAL31 promoters,and five pairs of bidirectional GAL1/GAL10 promoters.Overall,alternative regulatory controls for genome engineering tools can be developed to facilitate genomic engineering for synthetic biology and metabolic engineering applications.