Composability and Design of Parts for Large-Scale Pathway Engineering in Yeast

Yeasts can be powerful platforms for production of many industrially relevant molecules.  However, expression systems for predictable control of gene expression do not permit the construction of large multi-gene combinatorial libraries without multiple repetitions of promoters and terminators, compromising construct stability.

Therefore, to enable design and construction of these libraries in yeast, it is necessary to develop assembly methods and parts capable of achieving the size and diversity needed to gather useful information concerning pathway design. 

Yeast promoters are among the most heavily studied genetic elements, yet only a handful are in use industrially.  Even fewer terminators are well understood and in use.  Recent literature has demonstrated that terminators can have a profound effect on gene expression.  Yet, it remains unknown if this effect is independent of the promoter. To this end, the variation in expression of GFP was measured for 244 promoter-terminator combinations.  This value is compared to the strength measured using a standard promoter or terminator.  These data can be applied to optimize expression of metabolic pathways, and the approach extended to characterize the behavior of new parts, natural or synthetic.