Construction, characterization and application of a genome-wide promoter library in
. MOE Key Laboratory of Bioinformatics and Centre for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.. College of Life Sciences, Capital Normal University, Beijing 100048, China.. MOE Key Laboratory of Bioinformatics and Bioinformatics Division, Center for Synthetic and Systems Biology, TNLIST/Department of Automation, Tsinghua University, Beijing 100084, China.. School of Biological Sciences, The King’s Buildings, University of Edinburgh, Edinburgh, EH9 3BF, UK
Promoters are critical elements to control gene expression but could behave differently under various growth conditions. Here we report the construction of a genome-wide promoter library, in which each native promoter in was cloned upstream of a yellow fluorescent protein (YFP) reporter gene. Nine libraries were arbitrarily defined and assembled in bacteria. The resulting pools of promoters could be prepared and transformed into a yeast strain either as centromeric plasmids or integrated into a genomic locus upon enzymatic treatment. Using fluorescence activated cell sorting, we classified the yeast strains based on YFP fluorescence intensity and arbitrarily divided the entire library into 12 bins, representing weak to strong promoters. Several strong promoters were identified from the most active bins and their activities were assayed under different growth conditions. Finally, these promoters were applied to drive the expression of genes in xylose utilization to improve fermentation efficiency. Together, this library could provide a quick solution to identify and utilize desired promoters under user-defined growth conditions.